springboot+mybatisplus+flowable+mysql兼容达梦数据库

一、达梦数据库配置 

从数据库安装目录（/dm/dm8dbms/drivers/jdbc）下复制DmJdbcDriver18.jar驱动包（18对应jdk1.8）到项目中/resources/lib目录下（没有就自己建），然后复制下面maven引用。这里踩了坑，就是没有从安装目录复制驱动包，导致不兼容。

    com.dameng
    Dm8JdbcDriver18
    1.0.0.RELEASE
    system
    ${project.basedir}/src/main/resources/lib/DmJdbcDriver18.jar

 application.yml代码示例，clobAsString=true是因为mysql的text字段到达梦数据库的时候不会转成string，报错

driver-class-name: dm.jdbc.driver.DmDriver
url: jdbc:dm://127.0.0.1:5236?schema=xxx&clobAsString=true
username: xxx
password: xxx

 二、修改org.flowable.common.engine.impl.AbstractEngineConfiguration中源码

数据库配置完成后启动项目报错

Caused by: org.flowable.common.engine.api.FlowableException: couldn’t deduct database type from database product name ‘DM DBMS’

自动加载数据源时，flowable无法识别DM数据库类型，采用覆盖源码，设置成MySQL或者Oracle的数据库类型，需要修改文件：

在项目中创建org.flowable.common.engine.impl.AbstractEngineConfiguration文件（这边路径必须一致，打包时会覆盖源文件）

public static Properties getDefaultDatabaseTypeMappings() {
        Properties databaseTypeMappings = new Properties();
        databaseTypeMappings.setProperty("H2", DATABASE_TYPE_H2);
        databaseTypeMappings.setProperty("HSQL Database Engine", DATABASE_TYPE_HSQL);
        databaseTypeMappings.setProperty("MySQL", DATABASE_TYPE_MYSQL);
        databaseTypeMappings.setProperty("MariaDB", DATABASE_TYPE_MYSQL);
        databaseTypeMappings.setProperty("Oracle", DATABASE_TYPE_ORACLE);
        databaseTypeMappings.setProperty(PRODUCT_NAME_POSTGRES, DATABASE_TYPE_POSTGRES);
        databaseTypeMappings.setProperty("Microsoft SQL Server", DATABASE_TYPE_MSSQL);
        databaseTypeMappings.setProperty(DATABASE_TYPE_DB2, DATABASE_TYPE_DB2);
        databaseTypeMappings.setProperty("DB2", DATABASE_TYPE_DB2);
        databaseTypeMappings.setProperty("DB2/NT", DATABASE_TYPE_DB2);
        databaseTypeMappings.setProperty("DB2/NT64", DATABASE_TYPE_DB2);
        databaseTypeMappings.setProperty("DB2 UDP", DATABASE_TYPE_DB2);
        databaseTypeMappings.setProperty("DB2/LINUX", DATABASE_TYPE_DB2);
        databaseTypeMappings.setProperty("DB2/LINUX390", DATABASE_TYPE_DB2);
        databaseTypeMappings.setProperty("DB2/LINUXX8664", DATABASE_TYPE_DB2);
        databaseTypeMappings.setProperty("DB2/LINUXZ64", DATABASE_TYPE_DB2);
        databaseTypeMappings.setProperty("DB2/LINUXPPC64", DATABASE_TYPE_DB2);
        databaseTypeMappings.setProperty("DB2/LINUXPPC64LE", DATABASE_TYPE_DB2);
        databaseTypeMappings.setProperty("DB2/400 SQL", DATABASE_TYPE_DB2);
        databaseTypeMappings.setProperty("DB2/6000", DATABASE_TYPE_DB2);
        databaseTypeMappings.setProperty("DB2 UDB iSeries", DATABASE_TYPE_DB2);
        databaseTypeMappings.setProperty("DB2/AIX64", DATABASE_TYPE_DB2);
        databaseTypeMappings.setProperty("DB2/HPUX", DATABASE_TYPE_DB2);
        databaseTypeMappings.setProperty("DB2/HP64", DATABASE_TYPE_DB2);
        databaseTypeMappings.setProperty("DB2/SUN", DATABASE_TYPE_DB2);
        databaseTypeMappings.setProperty("DB2/SUN64", DATABASE_TYPE_DB2);
        databaseTypeMappings.setProperty("DB2/PTX", DATABASE_TYPE_DB2);
        databaseTypeMappings.setProperty("DB2/2", DATABASE_TYPE_DB2);
        databaseTypeMappings.setProperty("DB2 UDB AS400", DATABASE_TYPE_DB2);
        databaseTypeMappings.setProperty(PRODUCT_NAME_CRDB, DATABASE_TYPE_COCKROACHDB);
        databaseTypeMappings.setProperty("DM DBMS", DATABASE_TYPE_ORACLE);// 加入达梦支持 可以直接使用ORACLE或者MYSQL的
        return databaseTypeMappings;
    }

三、修改liquibase.database.core中源码

liquibase官网版本支持的数据库类型有：cockroachdb、db2、db2z、Derby、firebird、H2、hsqldb、informix，ingres、MariaDB、mock、Microsoft SQL Server、MySQL、Oracle、Postgres、Sqlite、Sybase。对国产化数据库达梦的适配至少需要进行如下的修改

1.第一步需要创建新的class，继承AbstractJdbcDatabase，并且放在liquibase.database.core包下，这样Liquibase才会识别DM DBMS类型，这里是仿照OracleDatabase的做的

删除setConnection方法；

修改PRODUCT_NAME常量值为“DM DBMS”；

修改getDefaultPort方法，返回5236；

修改getShortName方法，返回dm

修改getDefaultDriver方法，返回达梦的Driver。

具体代码如下

package liquibase.database.core;

import liquibase.CatalogAndSchema;
import liquibase.Scope;
import liquibase.database.AbstractJdbcDatabase;
import liquibase.database.DatabaseConnection;
import liquibase.database.OfflineConnection;
import liquibase.database.jvm.JdbcConnection;
import liquibase.exception.DatabaseException;
import liquibase.exception.UnexpectedLiquibaseException;
import liquibase.exception.ValidationErrors;
import liquibase.executor.ExecutorService;
import liquibase.logging.LogService;
import liquibase.logging.LogType;
import liquibase.statement.DatabaseFunction;
import liquibase.statement.SequenceCurrentValueFunction;
import liquibase.statement.SequenceNextValueFunction;
import liquibase.statement.core.RawCallStatement;
import liquibase.statement.core.RawSqlStatement;
import liquibase.structure.DatabaseObject;
import liquibase.structure.core.Catalog;
import liquibase.structure.core.Index;
import liquibase.structure.core.PrimaryKey;
import liquibase.structure.core.Schema;
import liquibase.util.JdbcUtils;
import liquibase.util.StringUtils;

import java.lang.reflect.Method;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Properties;
import java.util.ResourceBundle;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import static java.util.ResourceBundle.getBundle;

/**
 * Encapsulates Oracle database support.
 */
public class DmDatabase extends AbstractJdbcDatabase {
    private static final Pattern PROXY_USER = Pattern.compile(".*(?:thin|oci)\\:(.+)/@.*");

    public static final String PRODUCT_NAME = "DM DBMS";
    private static ResourceBundle coreBundle = getBundle("liquibase/i18n/liquibase-core");
    protected final int SHORT_IDENTIFIERS_LENGTH = 30;
    protected final int LONG_IDENTIFIERS_LEGNTH = 128;
    public static final int ORACLE_12C_MAJOR_VERSION = 12;

    private Set reservedWords = new HashSet();
    private Set userDefinedTypes;
    private Map savedSessionNlsSettings;

    private Boolean canAccessDbaRecycleBin;
    private Integer databaseMajorVersion;
    private Integer databaseMinorVersion;

    /**
     * Default constructor for an object that represents the Oracle Database DBMS.
     */
    public DmDatabase() {
        super.unquotedObjectsAreUppercased = true;
        //noinspection HardCodedStringLiteral
        super.setCurrentDateTimeFunction("SYSTIMESTAMP");
        // Setting list of Oracle's native functions
        //noinspection HardCodedStringLiteral
        dateFunctions.add(new DatabaseFunction("SYSDATE"));
        //noinspection HardCodedStringLiteral
        dateFunctions.add(new DatabaseFunction("SYSTIMESTAMP"));
        //noinspection HardCodedStringLiteral
        dateFunctions.add(new DatabaseFunction("CURRENT_TIMESTAMP"));
        //noinspection HardCodedStringLiteral
        super.sequenceNextValueFunction = "%s.nextval";
        //noinspection HardCodedStringLiteral
        super.sequenceCurrentValueFunction = "%s.currval";
    }

    @Override
    public int getPriority() {
        return PRIORITY_DEFAULT;
    }

    private final void tryProxySessionn(final String url, final Connection con) {
        Matcher m = PROXY_USER.matcher(url);
        if (m.matches()) {
            Properties props = new Properties();
            props.put("PROXY_USER_NAME", m.group(1));
            try {
                Method method = con.getClass().getMethod("openProxySession", int.class, Properties.class);
                method.setAccessible(true);
                method.invoke(con, 1, props);
            } catch (Exception e) {
                Scope.getCurrentScope().getLog(getClass()).info(LogType.LOG, "Could not open proxy session on OracleDatabase: " + e.getCause().getMessage());
            }
        }
    }

    @Override
    public void setConnection(DatabaseConnection conn) {
        //noinspection HardCodedStringLiteral,HardCodedStringLiteral,HardCodedStringLiteral,HardCodedStringLiteral,
        // HardCodedStringLiteral
        //noinspection HardCodedStringLiteral,HardCodedStringLiteral,HardCodedStringLiteral,HardCodedStringLiteral,
        // HardCodedStringLiteral
        reservedWords.addAll(Arrays.asList("GROUP", "USER", "SESSION", "PASSWORD", "RESOURCE", "START", "SIZE", "UID", "DESC", "ORDER")); //more reserved words not returned by driver

        Connection sqlConn = null;
        if (!(conn instanceof OfflineConnection)) {
            try {
                /*
                 * Don't try to call getWrappedConnection if the conn instance is
                 * is not a JdbcConnection. This happens for OfflineConnection.
                 * see https://liquibase.jira.com/browse/CORE-2192
                 */
                if (conn instanceof JdbcConnection) {
                    sqlConn = ((JdbcConnection) conn).getWrappedConnection();
                }
            } catch (Exception e) {
                throw new UnexpectedLiquibaseException(e);
            }

            if (sqlConn != null) {
                tryProxySessionn(conn.getURL(), sqlConn);

                try {
                    //noinspection HardCodedStringLiteral
                    reservedWords.addAll(Arrays.asList(sqlConn.getMetaData().getSQLKeywords().toUpperCase().split(",\\s*")));
                } catch (SQLException e) {
                    //noinspection HardCodedStringLiteral
                    LogService.getLog(getClass()).info(LogType.LOG, "Could get sql keywords on OracleDatabase: " + e.getMessage());
                    //can not get keywords. Continue on
                }
                try {
                    Method method = sqlConn.getClass().getMethod("setRemarksReporting", Boolean.TYPE);
                    method.setAccessible(true);
                    method.invoke(sqlConn, true);
                } catch (Exception e) {
                    //noinspection HardCodedStringLiteral
                    LogService.getLog(getClass()).info(LogType.LOG, "Could not set remarks reporting on OracleDatabase: " + e.getMessage());

                    //cannot set it. That is OK
                }

                Statement statement = null;
                ResultSet resultSet = null;
                try {
                    statement = sqlConn.createStatement();
                    //noinspection HardCodedStringLiteral
                    resultSet = statement.executeQuery("SELECT value FROM v$parameter WHERE name = 'compatible'");
                    String compatibleVersion = null;
                    if (resultSet.next()) {
                        //noinspection HardCodedStringLiteral
                        compatibleVersion = resultSet.getString("value");
                    }
                    if (compatibleVersion != null) {
                        Matcher majorVersionMatcher = Pattern.compile("(\\d+)\\.(\\d+)\\..*").matcher(compatibleVersion);
                        if (majorVersionMatcher.matches()) {
                            this.databaseMajorVersion = Integer.valueOf(majorVersionMatcher.group(1));
                            this.databaseMinorVersion = Integer.valueOf(majorVersionMatcher.group(2));
                        }
                    }
                } catch (SQLException e) {
                    @SuppressWarnings("HardCodedStringLiteral") String message = "Cannot read from v$parameter: " + e.getMessage();

                    //noinspection HardCodedStringLiteral
                    LogService.getLog(getClass()).info(LogType.LOG, "Could not set check compatibility mode on OracleDatabase, assuming not running in any sort of compatibility mode: " + message);
                } finally {
                    JdbcUtils.close(resultSet, statement);
                }


            }
        }
        super.setConnection(conn);
    }

    @Override
    public String getShortName() {
        //noinspection HardCodedStringLiteral
        return "dm";
    }

    @Override
    protected String getDefaultDatabaseProductName() {
        //noinspection HardCodedStringLiteral
        return "dm";
    }

    @Override
    public int getDatabaseMajorVersion() throws DatabaseException {
        if (databaseMajorVersion == null) {
            return super.getDatabaseMajorVersion();
        } else {
            return databaseMajorVersion;
        }
    }

    @Override
    public int getDatabaseMinorVersion() throws DatabaseException {
        if (databaseMinorVersion == null) {
            return super.getDatabaseMinorVersion();
        } else {
            return databaseMinorVersion;
        }
    }

    @Override
    public Integer getDefaultPort() {
        return 5236;
    }

    @Override
    public String getJdbcCatalogName(CatalogAndSchema schema) {
        return null;
    }

    @Override
    public String getJdbcSchemaName(CatalogAndSchema schema) {
        return correctObjectName((schema.getCatalogName() == null) ? schema.getSchemaName() : schema.getCatalogName(), Schema.class);
    }

    @Override
    protected String getAutoIncrementClause(final String generationType, final Boolean defaultOnNull) {
        if (StringUtils.isEmpty(generationType)) {
            return "";
        }

        String autoIncrementClause = "GENERATED %s AS IDENTITY"; // %s -- [ ALWAYS | BY DEFAULT [ ON NULL ] ]
        String generationStrategy = generationType;
        if (Boolean.TRUE.equals(defaultOnNull) && generationType.toUpperCase().equals("BY DEFAULT")) {
            generationStrategy += " ON NULL";
        }
        return String.format(autoIncrementClause, generationStrategy);
    }

    @Override
    public String generatePrimaryKeyName(String tableName) {
        if (tableName.length() > 27) {
            //noinspection HardCodedStringLiteral
            return "PK_" + tableName.toUpperCase(Locale.US).substring(0, 27);
        } else {
            //noinspection HardCodedStringLiteral
            return "PK_" + tableName.toUpperCase(Locale.US);
        }
    }

    @Override
    public boolean supportsInitiallyDeferrableColumns() {
        return true;
    }

    @Override
    public boolean isReservedWord(String objectName) {
        return reservedWords.contains(objectName.toUpperCase());
    }

    @Override
    public boolean supportsSequences() {
        return true;
    }

    /**
     * Oracle supports catalogs in liquibase terms
     *
     * @return false
     */
    @Override
    public boolean supportsSchemas() {
        return false;
    }

    @Override
    protected String getConnectionCatalogName() throws DatabaseException {
        if (getConnection() instanceof OfflineConnection) {
            return getConnection().getCatalog();
        }
        try {
            //noinspection HardCodedStringLiteral
            return ExecutorService.getInstance().getExecutor(this).queryForObject(new RawCallStatement("select sys_context( 'userenv', 'current_schema' ) from dual"), String.class);
        } catch (Exception e) {
            //noinspection HardCodedStringLiteral
            LogService.getLog(getClass()).info(LogType.LOG, "Error getting default schema", e);
        }
        return null;
    }

    @Override
    public boolean isCorrectDatabaseImplementation(DatabaseConnection conn) throws DatabaseException {
        return PRODUCT_NAME.equalsIgnoreCase(conn.getDatabaseProductName());
    }

    @Override
    public String getDefaultDriver(String url) {
        //noinspection HardCodedStringLiteral
        if (url.startsWith("jdbc:dm")) {
            return "dm.jdbc.driver.DmDriver";
        }
        return null;
    }

    @Override
    public String getDefaultCatalogName() {//NOPMD
        return (super.getDefaultCatalogName() == null) ? null : super.getDefaultCatalogName().toUpperCase(Locale.US);
    }

    /**
     * 
Returns an Oracle date literal with the same value as a string formatted using ISO 8601.
     *
     * 
Convert an ISO8601 date string to one of the following results:     * to_date('1995-05-23', 'YYYY-MM-DD')     * to_date('1995-05-23 09:23:59', 'YYYY-MM-DD HH24:MI:SS')
     * 
     * Implementation restriction:
     * Currently, only the following subsets of ISO8601 are supported:
     * 
     * 
YYYY-MM-DD
     * 
YYYY-MM-DDThh:mm:ss
     * 
     */    @Override    public String getDateLiteral(String isoDate) {        String normalLiteral = super.getDateLiteral(isoDate);        if (isDateOnly(isoDate)) {            StringBuffer val = new StringBuffer();            //noinspection HardCodedStringLiteral            val.append("TO_DATE(");            val.append(normalLiteral);            //noinspection HardCodedStringLiteral            val.append(", 'YYYY-MM-DD')");            return val.toString();        } else if (isTimeOnly(isoDate)) {            StringBuffer val = new StringBuffer();            //noinspection HardCodedStringLiteral            val.append("TO_DATE(");            val.append(normalLiteral);            //noinspection HardCodedStringLiteral            val.append(", 'HH24:MI:SS')");            return val.toString();        } else if (isTimestamp(isoDate)) {            StringBuffer val = new StringBuffer(26);            //noinspection HardCodedStringLiteral            val.append("TO_TIMESTAMP(");            val.append(normalLiteral);            //noinspection HardCodedStringLiteral            val.append(", 'YYYY-MM-DD HH24:MI:SS.FF')");            return val.toString();        } else if (isDateTime(isoDate)) {            int seppos = normalLiteral.lastIndexOf('.');            if (seppos != -1) {                normalLiteral = normalLiteral.substring(0, seppos) + "'";            }            StringBuffer val = new StringBuffer(26);            //noinspection HardCodedStringLiteral            val.append("TO_DATE(");            val.append(normalLiteral);            //noinspection HardCodedStringLiteral            val.append(", 'YYYY-MM-DD HH24:MI:SS')");            return val.toString();        }        //noinspection HardCodedStringLiteral        return "UNSUPPORTED:" + isoDate;    }    @Override    public boolean isSystemObject(DatabaseObject example) {        if (example == null) {            return false;        }        if (this.isLiquibaseObject(example)) {            return false;        }        if (example instanceof Schema) {            //noinspection HardCodedStringLiteral,HardCodedStringLiteral,HardCodedStringLiteral,HardCodedStringLiteral            if ("SYSTEM".equals(example.getName()) || "SYS".equals(example.getName()) || "CTXSYS".equals(example.getName()) || "XDB".equals(example.getName())) {                return true;            }            //noinspection HardCodedStringLiteral,HardCodedStringLiteral,HardCodedStringLiteral,HardCodedStringLiteral            if ("SYSTEM".equals(example.getSchema().getCatalogName()) || "SYS".equals(example.getSchema().getCatalogName()) || "CTXSYS".equals(example.getSchema().getCatalogName()) || "XDB".equals(example.getSchema().getCatalogName())) {                return true;            }        } else if (isSystemObject(example.getSchema())) {            return true;        }        if (example instanceof Catalog) {            //noinspection HardCodedStringLiteral,HardCodedStringLiteral,HardCodedStringLiteral,HardCodedStringLiteral            if (("SYSTEM".equals(example.getName()) || "SYS".equals(example.getName()) || "CTXSYS".equals(example.getName()) || "XDB".equals(example.getName()))) {                return true;            }        } else if (example.getName() != null) {            //noinspection HardCodedStringLiteral            if (example.getName().startsWith("BIN$")) { //oracle deleted table                boolean filteredInOriginalQuery = this.canAccessDbaRecycleBin();                if (!filteredInOriginalQuery) {                    filteredInOriginalQuery = StringUtils.trimToEmpty(example.getSchema().getName()).equalsIgnoreCase(this.getConnection().getConnectionUserName());                }                if (filteredInOriginalQuery) {                    return !((example instanceof PrimaryKey) || (example instanceof Index) || (example instanceof                            liquibase.statement.UniqueConstraint));                } else {                    return true;                }            } else //noinspection HardCodedStringLiteral                if (example.getName().startsWith("AQ$")) { //oracle AQ tables                    return true;                } else //noinspection HardCodedStringLiteral                    if (example.getName().startsWith("DR$")) { //oracle index tables                        return true;                    } else //noinspection HardCodedStringLiteral                        if (example.getName().startsWith("SYS_IOT_OVER")) { //oracle system table                            return true;                        } else //noinspection HardCodedStringLiteral,HardCodedStringLiteral                            if ((example.getName().startsWith("MDRT_") || example.getName().startsWith("MDRS_")) && example.getName().endsWith("$")) {                                // CORE-1768 - Oracle creates these for spatial indices and will remove them when the index is removed.                                return true;                            } else //noinspection HardCodedStringLiteral                                if (example.getName().startsWith("MLOG$_")) { //Created by materliaized view logs for every table that is part of a materialized view. Not available for DDL operations.                                    return true;                                } else //noinspection HardCodedStringLiteral                                    if (example.getName().startsWith("RUPD$_")) { //Created by materialized view log tables using primary keys. Not available for DDL operations.                                        return true;                                    } else //noinspection HardCodedStringLiteral                                        if (example.getName().startsWith("WM$_")) { //Workspace Manager backup tables.                                            return true;                                        } else //noinspection HardCodedStringLiteral                                            if ("CREATE$JAVA$LOB$TABLE".equals(example.getName())) { //This table contains the name of the Java object, the date it was loaded, and has a BLOB column to store the Java object.                                                return true;                                            } else //noinspection HardCodedStringLiteral                                                if ("JAVA$CLASS$MD5$TABLE".equals(example.getName())) { //This is a hash table that tracks the loading of Java objects into a schema.                                                    return true;                                                } else //noinspection HardCodedStringLiteral                                                    if (example.getName().startsWith("ISEQ$$_")) { //System-generated sequence                                                        return true;                                                    } else //noinspection HardCodedStringLiteral                                                        if (example.getName().startsWith("USLOG$")) { //for update materialized view                                                            return true;                                                        } else if (example.getName().startsWith("SYS_FBA")) { //for Flashback tables                                                            return true;                                                        }        }        return super.isSystemObject(example);    }    @Override    public boolean supportsTablespaces() {        return true;    }    @Override    public boolean supportsAutoIncrement() {        // Oracle supports Identity beginning with version 12c        boolean isAutoIncrementSupported = false;        try {            if (getDatabaseMajorVersion() >= 12) {                isAutoIncrementSupported = true;            }            // Returning true will generate create table command with 'IDENTITY' clause, example:            // CREATE TABLE AutoIncTest (IDPrimaryKey NUMBER(19) GENERATED BY DEFAULT AS IDENTITY NOT NULL, TypeID NUMBER(3) NOT NULL, Description NVARCHAR2(50), CONSTRAINT PK_AutoIncTest PRIMARY KEY (IDPrimaryKey));            // While returning false will continue to generate create table command without 'IDENTITY' clause, example:            // CREATE TABLE AutoIncTest (IDPrimaryKey NUMBER(19) NOT NULL, TypeID NUMBER(3) NOT NULL, Description NVARCHAR2(50), CONSTRAINT PK_AutoIncTest PRIMARY KEY (IDPrimaryKey));        } catch (DatabaseException ex) {            isAutoIncrementSupported = false;        }        return isAutoIncrementSupported;    }//    public Set findUniqueConstraints(String schema) throws DatabaseException {//        Set returnSet = new HashSet();////        List

四、修改 liquibase.datatype.core.BooleanType类，以支持达梦的bit类型与java的Boolean类型的转换 

在toDatabaseDataType方法中添加DmDatabase的支持

在isNumericBoolean方法中添加DmDatabase类型

具体代码如下：

    @Override
    public DatabaseDataType toDatabaseDataType(Database database) {
        String originalDefinition = StringUtil.trimToEmpty(getRawDefinition());
        if ((database instanceof Firebird3Database)) {
            return new DatabaseDataType("BOOLEAN");
        }
 
        if ((database instanceof AbstractDb2Database) || (database instanceof FirebirdDatabase)) {
            return new DatabaseDataType("SMALLINT");
        } else if (database instanceof MSSQLDatabase) {
            return new DatabaseDataType(database.escapeDataTypeName("bit"));
        } else if (database instanceof MySQLDatabase) {
            if (originalDefinition.toLowerCase(Locale.US).startsWith("bit")) {
                return new DatabaseDataType("BIT", getParameters());
            }
            return new DatabaseDataType("BIT", 1);
        } else if (database instanceof OracleDatabase) {
            return new DatabaseDataType("NUMBER", 1);
        } else if ((database instanceof SybaseASADatabase) || (database instanceof SybaseDatabase)) {
            return new DatabaseDataType("BIT");
        } else if (database instanceof DerbyDatabase) {
            if (((DerbyDatabase) database).supportsBooleanDataType()) {
                return new DatabaseDataType("BOOLEAN");
            } else {
                return new DatabaseDataType("SMALLINT");
            }
        } else if (database.getClass().isAssignableFrom(DB2Database.class)) {
            if (((DB2Database) database).supportsBooleanDataType())
                return new DatabaseDataType("BOOLEAN");
            else
                return new DatabaseDataType("SMALLINT");
        } else if (database instanceof HsqlDatabase) {
            return new DatabaseDataType("BOOLEAN");
        } else if (database instanceof PostgresDatabase) {
            if (originalDefinition.toLowerCase(Locale.US).startsWith("bit")) {
                return new DatabaseDataType("BIT", getParameters());
            }
        } else if(database instanceof DmDatabase) {
            return new DatabaseDataType("bit");
        }
 
        return super.toDatabaseDataType(database);
    }
 
    @Override
    public String objectToSql(Object value, Database database) {
        if ((value == null) || "null".equals(value.toString().toLowerCase(Locale.US))) {
            return null;
        }
 
        String returnValue;
        if (value instanceof String) {
            value = ((String) value).replaceAll("'", "");
            if ("true".equals(((String) value).toLowerCase(Locale.US)) || "1".equals(value) || "b'1'".equals(((String) value).toLowerCase(Locale.US)) || "t".equals(((String) value).toLowerCase(Locale.US)) || ((String) value).toLowerCase(Locale.US).equals(this.getTrueBooleanValue(database).toLowerCase(Locale.US))) {
                returnValue = this.getTrueBooleanValue(database);
            } else if ("false".equals(((String) value).toLowerCase(Locale.US)) || "0".equals(value) || "b'0'".equals(
                    ((String) value).toLowerCase(Locale.US)) || "f".equals(((String) value).toLowerCase(Locale.US)) || ((String) value).toLowerCase(Locale.US).equals(this.getFalseBooleanValue(database).toLowerCase(Locale.US))) {
                returnValue = this.getFalseBooleanValue(database);
            } else {
                throw new UnexpectedLiquibaseException("Unknown boolean value: " + value);
            }
        } else if (value instanceof Long) {
            if (Long.valueOf(1).equals(value)) {
                returnValue = this.getTrueBooleanValue(database);
            } else {
                returnValue = this.getFalseBooleanValue(database);
            }
        } else if (value instanceof Number) {
            if (value.equals(1) || "1".equals(value.toString()) || "1.0".equals(value.toString())) {
                returnValue = this.getTrueBooleanValue(database);
            } else {
                returnValue = this.getFalseBooleanValue(database);
            }
        } else if (value instanceof DatabaseFunction) {
            return value.toString();
        } else if (value instanceof Boolean) {
            if (((Boolean) value)) {
                returnValue = this.getTrueBooleanValue(database);
            } else {
                returnValue = this.getFalseBooleanValue(database);
            }
        } else {
            throw new UnexpectedLiquibaseException("Cannot convert type " + value.getClass() + " to a boolean value");
        }
 
        return returnValue;
    }
 
    protected boolean isNumericBoolean(Database database) {
        if (database instanceof DerbyDatabase) {
            return !((DerbyDatabase) database).supportsBooleanDataType();
        } else if (database.getClass().isAssignableFrom(DB2Database.class)) {
            return !((DB2Database) database).supportsBooleanDataType();
        }
        return (database instanceof Db2zDatabase) || (database instanceof DB2Database) || (database instanceof FirebirdDatabase) || (database instanceof
                MSSQLDatabase) || (database instanceof MySQLDatabase) || (database instanceof OracleDatabase) ||
                (database instanceof SQLiteDatabase) || (database instanceof SybaseASADatabase) || (database instanceof
                SybaseDatabase) || (database instanceof DmDatabase);
    }
 
    /**
     * The database-specific value to use for "false" "boolean" columns.
     */
    public String getFalseBooleanValue(Database database) {
        if (isNumericBoolean(database)) {
            return "0";
        }
        if (database instanceof InformixDatabase) {
            return "'f'";
        }
        return "FALSE";
    }
 
    /**
     * The database-specific value to use for "true" "boolean" columns.
     */
    public String getTrueBooleanValue(Database database) {
        if (isNumericBoolean(database)) {
            return "1";
        }
        if (database instanceof InformixDatabase) {
            return "'t'";
        }
        return "TRUE";
    }
 
    @Override
    public LoadDataChange.LOAD_DATA_TYPE getLoadTypeName() {
        return LoadDataChange.LOAD_DATA_TYPE.BOOLEAN;
    }

五、修改com.alibaba.druid.pool.DruidPooledStatement源码 

由于达梦数据库不能自动转换true/false为1/0，这里覆盖了com.alibaba.druid.pool.DruidPooledStatement，将其中的executeUpdate和execute方法中待执行的SQL语句做了转换。

    @Override
    public final boolean execute(String sql) throws SQLException {
        checkOpen();

        incrementExecuteCount();
        transactionRecord(sql);

        try {
            if (StringUtils.isNotEmpty(sql)){
                sql = sql.replace("TRUE", "1");
                sql = sql.replace("FALSE", "0");
            }
            return stmt.execute(sql);
        } catch (Throwable t) {
            errorCheck(t);
            throw checkException(t, sql);
        }
    }

六、mysql中sql语法的兼容达梦修改

1. “要替换成空字符串，不能在sql中使用“符号，关键字问题的话，在字段后面加下划线_

2. sql中的
   where或者连接表时的条件字段类型必须相同
   ，如t1.id=t2.id，不能一个是varchar一个是bigint，两个的字段类型必须相同。
   达梦连接表时条件字段类型不一样会报错。

3. 字段别名不能使用单引号，如
   t1.id
    as ‘user_id’。
   条件不能使用双引号
   ，要使用单引号如where tenant_id = ‘000000’。

4. 如果确实需要使用两边不兼容的函数或者sql语句
   ，如需要使用group_concat函数，要写两条sql，分别对应mysql数据库与达梦数据库
   ，在xml上加databaseId，代码如下

       
           GROUP_CONCAT(b4.dept_name) user_dept_name,
       
       
           WM_CONCAT(b4.dept_name) user_dept_name,
       
   

   本文参考链接：
   Flowable工作流兼容达梦数据库