import liquibase.structure.core.Column; //导入依赖的package包/类
@Override
public Sql[] generateSql(RemoveChangeSetRanStatusStatement statement, Database database, SqlGeneratorChain sqlGeneratorChain) {
    ChangeSet changeSet = statement.getChangeSet();
    String tmpTable = UUID.randomUUID().toString().replaceAll("-", "");
    String catalogName = database.getLiquibaseCatalogName();
    String schemaName = database.getDefaultSchemaName();
    String tableName = database.getDatabaseChangeLogTableName();
    CreateTableAsSelectStatement createTableAsSelectStatement = new CreateTableAsSelectStatement(catalogName, schemaName, tableName, tmpTable)
            .addColumnNames("ID", "AUTHOR", "FILENAME", "DATEEXECUTED", "ORDEREXECUTED", "EXECTYPE", "MD5SUM", "DESCRIPTION", "COMMENTS", "TAG", "LIQUIBASE", "CONTEXTS", "LABELS", "DEPLOYMENT_ID")
            .setWhereCondition(database.escapeObjectName("ID", Column.class) + " != ? " +
                    "AND " + database.escapeObjectName("FILENAME", Column.class) + " != ?")
            .addWhereParameters(changeSet.getId(), changeSet.getFilePath());

    return CustomSqlGenerator.generateSql(database,
            createTableAsSelectStatement,
            new DropTableStatement(catalogName, schemaName, tableName, false),
            new RenameTableStatement(catalogName, schemaName, tmpTable, tableName));
}
 

import liquibase.structure.core.Column; //导入依赖的package包/类
@Override
public Sql[] generateSql(TagDatabaseStatement statement, Database database, SqlGeneratorChain sqlGeneratorChain) {
    String catalogName = database.getLiquibaseCatalogName();
    String schemaName = database.getDefaultSchemaName();
    String tableName = database.getDatabaseChangeLogTableName();
    String tableNameEscaped = database.escapeObjectName(tableName, Table.class);
    String dateColumnNameEscaped = database.escapeObjectName("DATEEXECUTED", Column.class);
    String tagColumnNameEscaped = database.escapeObjectName("TAG", Column.class);
    String tempTable = UUID.randomUUID().toString().replaceAll("-", "");
    CreateTableAsSelectStatement createTableAsSelectStatement = new CreateTableAsSelectStatement(catalogName, schemaName, tableName, tempTable)
            .addColumnNames("ID", "AUTHOR", "FILENAME", "DATEEXECUTED", "ORDEREXECUTED", "EXECTYPE", "MD5SUM", "DESCRIPTION", "COMMENTS", "TAG", "LIQUIBASE", "CONTEXTS", "LABELS", "DEPLOYMENT_ID")
            .setWhereCondition(tableNameEscaped + "." + dateColumnNameEscaped + " NOT IN (SELECT MAX(" + tableNameEscaped + "." + dateColumnNameEscaped + ") " +
                    "FROM " + tableNameEscaped + ")");
    InsertAsSelectStatement insertAsSelectStatement = new InsertAsSelectStatement(catalogName, schemaName, tableName, tempTable)
            .addColumnNames("ID", "AUTHOR", "FILENAME", "DATEEXECUTED", "ORDEREXECUTED", "EXECTYPE", "MD5SUM", "DESCRIPTION", "COMMENTS", "'" + statement.getTag() + "'", "LIQUIBASE", "CONTEXTS", "LABELS", "DEPLOYMENT_ID")
            .setWhereCondition(tableNameEscaped + "." + dateColumnNameEscaped + " IN (SELECT MAX(" + tableNameEscaped + "." + dateColumnNameEscaped + ") FROM " + tableNameEscaped + ") AND ("
                    + tableNameEscaped + "." + tagColumnNameEscaped + " IS NULL OR " + tableNameEscaped + "." + tagColumnNameEscaped + " != ?)").addWhereParameters(statement.getTag());

    return CustomSqlGenerator.generateSql(database,
            createTableAsSelectStatement,
            insertAsSelectStatement,
            new DropTableStatement(catalogName, schemaName, tableName, false),
            new RenameTableStatement(catalogName, schemaName, tempTable, tableName));
}
 

import liquibase.structure.core.Column; //导入依赖的package包/类
@Override
public Sql[] generateSql(RemoveChangeSetRanStatusStatement statement, Database database, SqlGeneratorChain sqlGeneratorChain) {
    ChangeSet changeSet = statement.getChangeSet();
    String tmpTable = UUID.randomUUID().toString().replaceAll("-", "");
    String catalogName = database.getLiquibaseCatalogName();
    String schemaName = database.getDefaultSchemaName();
    String tableName = database.getDatabaseChangeLogTableName();
    CreateTableAsSelectStatement createTableAsSelectStatement = new CreateTableAsSelectStatement(catalogName, schemaName, tableName, tmpTable)
            .addColumnNames("ID", "AUTHOR", "FILENAME", "DATEEXECUTED", "ORDEREXECUTED", "EXECTYPE", "MD5SUM", "DESCRIPTION", "COMMENTS", "TAG", "LIQUIBASE", "CONTEXTS", "LABELS", "DEPLOYMENT_ID")
            .setWhereCondition(" NOT (" + database.escapeObjectName("ID", Column.class) + " = ? " +
                    "AND " + database.escapeObjectName("FILENAME", Column.class) + " = ?)")
            .addWhereParameters(changeSet.getId(), changeSet.getFilePath());

    return CustomSqlGenerator.generateSql(database,
            UserSessionSettings.syncDdlStart(),
            createTableAsSelectStatement,
            new DropTableStatement(catalogName, schemaName, tableName, false),
            new RenameTableStatement(catalogName, schemaName, tmpTable, tableName),
            UserSessionSettings.syncDdlStop());
}
 

import liquibase.structure.core.Column; //导入依赖的package包/类
/**
 * Generates the SQL for inserting the necessary record into the
 * <code>USER_SDO_GEOM_METADATA</code> table. This record must be present prior to creating the
 * spatial index.
 * 
 * @param statement
 *           the create spatial index statement.
 * @param database
 *           the database instance.
 * @return the SQL to insert the metadata record.
 */
protected String generateInsertMetadataSql(final CreateSpatialIndexStatement statement,
      final Database database) {
   final StringBuilder sql = new StringBuilder();
   sql.append("INSERT INTO user_sdo_geom_metadata ");
   sql.append("(table_name, column_name, diminfo, srid) ");
   final String tableName = statement.getTableName().trim();
   sql.append("VALUES ('").append(database.correctObjectName(tableName, Table.class));
   final String columnName = statement.getColumns()[0].trim();
   sql.append("', '").append(database.correctObjectName(columnName, Column.class));
   sql.append("', SDO_DIM_ARRAY(");
   sql.append("SDO_DIM_ELEMENT('Longitude', -180, 180, 0.005), ");
   sql.append("SDO_DIM_ELEMENT('Latitude', -90, 90, 0.005))");
   final Integer srid = statement.getSrid();
   if (srid == null) {
      sql.append(", NULL");
   } else {
      sql.append(", ").append(OracleSpatialUtils.EPSG_TO_ORACLE_FUNCTION).append("(")
            .append(srid).append(")");
   }
   sql.append(")");
   return sql.toString();
}
 

import liquibase.structure.core.Column; //导入依赖的package包/类
@Override
public Sql[] generateSql(final DropColumnStatement statement, final Database database,
      final SqlGeneratorChain sqlGeneratorChain) {

   String schemaName = statement.getSchemaName();
   if (schemaName == null) {
      schemaName = database.getDefaultSchemaName();
   }
   final String tableName = statement.getTableName();
   final String columnName = statement.getColumnName();
   final boolean isGeometryColumn = GeometryColumnsUtils.isGeometryColumn(database, schemaName,
         tableName, columnName);
   final List<Sql> list = new ArrayList<Sql>();
   if (isGeometryColumn) {
      dropSpatialIndexIfExists(statement.getCatalogName(), schemaName, tableName, database, list);
      final String sql = "CALL DropGeometryColumn('" + schemaName + "', '" + tableName + "', '"
            + columnName + "')";
      final Column column = getAffectedColumn(statement);
      final Sql dropGeometryColumn = new UnparsedSql(sql, column);
      list.add(dropGeometryColumn);
   } else {
      list.addAll(Arrays.asList(sqlGeneratorChain.generateSql(statement, database)));
   }
   return list.toArray(new Sql[list.size()]);
}
 

import liquibase.structure.core.Column; //导入依赖的package包/类
/**
 * Generates the {@link Index} example (taken from {@link IndexExistsPrecondition}).
 *
 * @param database
 *           the database instance.
 * @param schema
 *           the schema instance.
 * @param tableName
 *           the table name of the index.
 * @return the index example.
 */
protected Index getIndexExample(final Database database, final Schema schema,
      final String tableName) {
   final Index example = new Index();
   if (tableName != null) {
      example.setTable((Table) new Table().setName(
            database.correctObjectName(getTableName(), Table.class)).setSchema(schema));
   }
   example.setName(database.correctObjectName(getIndexName(), Index.class));
   if (StringUtils.trimToNull(getColumnNames()) != null) {
      for (final String columnName : getColumnNames().split("\\s*,\\s*")) {
         final Column column = new Column(database.correctObjectName(columnName, Column.class));
         example.getColumns().add(column);
      }
   }
   return example;
}
 

import liquibase.structure.core.Column; //导入依赖的package包/类
@Override
public void check(Database database) throws CustomPreconditionFailedException, CustomPreconditionErrorException {
    Column column = new Column(this.columnNames);
    UniqueConstraint uniqueConstraint = new UniqueConstraint(this.constraintName, null, null, this.tableName, column);
    boolean markFailed = false;
    try {
        if (!SnapshotGeneratorFactory.getInstance().has(uniqueConstraint, database)) {
            markFailed = true;
        }
    } catch (Exception e) {
        throw new CustomPreconditionErrorException("custom precondition check errored", e);
    }

    if (markFailed) {
        throw new CustomPreconditionFailedException(this.constraintName + " doesn't exist");
    }
}
 

import liquibase.structure.core.Column; //导入依赖的package包/类
private Sql[] generateMultipleColumnSql(DropColumnStatement dropColumnStatement, Database database, Map<String, String> columnsPreserved) {
    if (columnsPreserved == null) {
        throw new UnexpectedLiquibaseException("no columns to preserve");
    }
    List<Sql> result = new ArrayList<Sql>();
    Map<String, String> columnsPreservedCopy = new HashMap<String, String>(columnsPreserved);
    String alterTable;
    List<DropColumnStatement> columns = null;

    if (dropColumnStatement.isMultiple()) {
        columns = dropColumnStatement.getColumns();
        for (DropColumnStatement statement : columns) {
            columnsPreservedCopy.remove(statement.getColumnName());
        }
        alterTable = "ALTER TABLE " + database.escapeTableName(columns.get(0).getCatalogName(), columns.get(0).getSchemaName(), columns.get(0).getTableName()) + " REPLACE COLUMNS (";
    } else {
        columnsPreservedCopy.remove(dropColumnStatement.getColumnName());
        alterTable = "ALTER TABLE " + database.escapeTableName(dropColumnStatement.getCatalogName(), dropColumnStatement.getSchemaName(), dropColumnStatement.getTableName()) + " REPLACE COLUMNS (";
    }

    int i = 0;
    for (String columnName : columnsPreservedCopy.keySet()) {
        alterTable += database.escapeObjectName(columnName, Column.class) + " " + columnsPreservedCopy.get(columnName);
        if (i < columnsPreservedCopy.size() - 1) {
            alterTable += ",";
        } else {
            alterTable += ")";
        }
        i++;
    }

    if (dropColumnStatement.isMultiple()) {
        result.add(new UnparsedSql(alterTable, getAffectedColumns(columns)));
    } else {
        result.add(new UnparsedSql(alterTable, getAffectedColumn(dropColumnStatement)));
    }
    return result.toArray(new Sql[result.size()]);
}
 

import liquibase.structure.core.Column; //导入依赖的package包/类
private Column[] getAffectedColumns(List<DropColumnStatement> columns) {
    List<Column> affected = new ArrayList<Column>();
    for (DropColumnStatement column : columns) {
        affected.add(getAffectedColumn(column));
    }
    return affected.toArray(new Column[affected.size()]);
}
 

import liquibase.structure.core.Column; //导入依赖的package包/类
@Override
public Sql[] generateSql(TagDatabaseStatement statement, Database database, SqlGeneratorChain sqlGeneratorChain) {
    String catalogName = database.getLiquibaseCatalogName();
    String schemaName = database.getDefaultSchemaName();
    String tableName = database.getDatabaseChangeLogTableName();
    String tableNameEscaped = database.escapeTableName(catalogName, schemaName, tableName);
    String dateColumnNameEscaped = database.escapeObjectName("DATEEXECUTED", Column.class);
    String tagColumnNameEscaped = database.escapeObjectName("TAG", Column.class);
    String tmpTable = UUID.randomUUID().toString().replaceAll("-", "");
    CreateTableAsSelectStatement createTableAsSelectStatement = new CreateTableAsSelectStatement(catalogName, schemaName, tableName, tmpTable)
            .addColumnNames("ID", "AUTHOR", "FILENAME", "DATEEXECUTED", "ORDEREXECUTED", "EXECTYPE", "MD5SUM", "DESCRIPTION", "COMMENTS", "TAG", "LIQUIBASE", "CONTEXTS", "LABELS", "DEPLOYMENT_ID")
            .setWhereCondition(dateColumnNameEscaped + " != (SELECT MAX(" + dateColumnNameEscaped + ") " +
                    "FROM " + tableNameEscaped + ")");
    InsertAsSelectStatement insertAsSelectStatement = new InsertAsSelectStatement(database.getLiquibaseCatalogName(), database.getLiquibaseSchemaName(), database.getDatabaseChangeLogTableName(), tmpTable)
            .addColumnNames("ID", "AUTHOR", "FILENAME", "DATEEXECUTED", "ORDEREXECUTED", "EXECTYPE", "MD5SUM", "DESCRIPTION", "COMMENTS", "'" + statement.getTag() + "'", "LIQUIBASE", "CONTEXTS", "LABELS", "DEPLOYMENT_ID")
            .setWhereCondition(dateColumnNameEscaped + " = (SELECT MAX(" + dateColumnNameEscaped + ") FROM " + tableNameEscaped + ") AND ("
                    + tagColumnNameEscaped + " IS NULL OR " + tagColumnNameEscaped + " != ?)")
            .addWhereParameters(statement.getTag());

    return CustomSqlGenerator.generateSql(database,
            UserSessionSettings.syncDdlStart(),
            createTableAsSelectStatement,
            insertAsSelectStatement,
            new DropTableStatement(catalogName, schemaName, tableName, false),
            new RenameTableStatement(catalogName, schemaName, tmpTable, tableName),
            UserSessionSettings.syncDdlStop());
}
 

import liquibase.structure.core.Column; //导入依赖的package包/类
@Override
public Sql[] generateSql(final DropSpatialIndexStatement statement, final Database database,
      final SqlGeneratorChain sqlGeneratorChain) {
   final String indexName = statement.getIndexName();
   final Index example = new Index().setName(indexName);
   if (statement.getTableName() != null) {
      example.setTable((Table) new Table().setName(statement.getTableName()).setSchema(
            statement.getTableCatalogName(), statement.getTableSchemaName()));
   }
   Index index;
   try {
      index = SnapshotGeneratorFactory.getInstance().createSnapshot(example, database);
   } catch (final Exception e) {
      throw new UnexpectedLiquibaseException("Failed to create a snapshot of '" + indexName
            + "'", e);
   }

   final String tableName = index.getTable().getName();
   final Column column = index.getColumns().get(0);

   final StringBuilder sql = new StringBuilder();
   sql.append("DELETE FROM user_sdo_geom_metadata ");
   sql.append("WHERE table_name = '").append(database.correctObjectName(tableName, Table.class));
   sql.append("' AND column_name = '").append(
         database.correctObjectName(column.getName(), Column.class));
   sql.append("'");
   final UnparsedSql deleteMetadata = new UnparsedSql(sql.toString(),
         new View().setName("user_sdo_geom_metadata"));
   return new Sql[] { deleteMetadata };
}
 

import liquibase.structure.core.Column; //导入依赖的package包/类
/**
 * Generates the SQL for deleting any existing record from the
 * <code>USER_SDO_GEOM_METADATA</code> table. Typically this record shouldn't be present but we
 * must ensure that it does not already exist.
 * 
 * @param statement
 *           the create spatial index statement.
 * @param database
 *           the database instance.
 * @return the SQL to delete any existing metadata record.
 */
protected String generateDeleteMetadataSql(final CreateSpatialIndexStatement statement,
      final Database database) {
   final StringBuilder sql = new StringBuilder();
   sql.append("DELETE FROM user_sdo_geom_metadata ");
   final String tableName = statement.getTableName().trim();
   sql.append("WHERE table_name = '").append(database.correctObjectName(tableName, Table.class));
   final String columnName = statement.getColumns()[0].trim();
   sql.append("' AND column_name = '").append(
         database.correctObjectName(columnName, Column.class));
   sql.append("'");
   return sql.toString();
}
 

import liquibase.structure.core.Column; //导入依赖的package包/类
/**
 * @see liquibase.sqlgenerator.core.AddDefaultValueGenerator#generateSql(liquibase.statement.core.AddDefaultValueStatement, liquibase.database.Database, liquibase.sqlgenerator.SqlGeneratorChain)
 */
@Override
public Sql[] generateSql(AddDefaultValueStatement statement, Database database, SqlGeneratorChain sqlGeneratorChain) {
	Object defaultValue = statement.getDefaultValue();
       LiquibaseDataType defaultValueType = DataTypeFactory.getInstance().fromObject(defaultValue, database);
	return new Sql[]{
			new UnparsedSql("ALTER TABLE " + database.escapeTableName(statement.getCatalogName(), statement.getSchemaName(), statement.getTableName())
					+ " ADD  "
                       + database.escapeColumnName(statement.getCatalogName(), statement.getSchemaName(), statement.getTableName(), statement.getColumnName())
                       + " DEFAULT "
					+ (defaultValueType instanceof DateTimeType ?" TIMESTAMP ":(defaultValueType instanceof DateType ?" DATE ":(defaultValueType instanceof TimeType ?" TIME ":"")))
					+ defaultValueType.objectToSql(defaultValue, database),
					new Column().setRelation(new Table().setName(statement.getTableName()).setSchema(new Schema(statement.getCatalogName(), statement.getSchemaName())).setName(statement.getColumnName())))
	};
}
 

import liquibase.structure.core.Column; //导入依赖的package包/类
private Column getAffectedColumn(DropColumnStatement statement) {
    return new Column().setName(statement.getColumnName()).setRelation(new Table().setName(statement.getTableName()).setSchema(statement.getCatalogName(), statement.getSchemaName()));
}
 

import liquibase.structure.core.Column; //导入依赖的package包/类
@Override
public Sql[] generateSql(AddColumnStatement statement, Database database, SqlGeneratorChain sqlGeneratorChain) {
	String alterTable = "ALTER TABLE " + database.escapeTableName(statement.getCatalogName(), statement.getSchemaName(), statement.getTableName()) +
               " ADD " +
               database.escapeColumnName(statement.getCatalogName(), statement.getSchemaName(), statement.getTableName(), statement.getColumnName())
               + " " + DataTypeFactory.getInstance().fromDescription(statement.getColumnType() + (statement.isAutoIncrement() ? "{autoIncrement:true}" : ""), database).toDatabaseDataType(database);

	if (statement.isAutoIncrement() && database.supportsAutoIncrement()) {
		alterTable += " " + database.getAutoIncrementClause(null, null);
	}

	if (!statement.isNullable()) {
		alterTable += " NOT NULL";
	} else {
		if (database instanceof SybaseDatabase || database instanceof SybaseASADatabase) {
			alterTable += " NULL";
		}
	}

	if (statement.getDefaultValue()!=null){
		alterTable += " DEFAULT ";
		LiquibaseDataType defaultValueType = DataTypeFactory.getInstance().fromDescription(statement.getColumnType() + (statement.isAutoIncrement() ? "{autoIncrement:true}" : ""), database);
		alterTable +=(defaultValueType instanceof DateTimeType ?" TIMESTAMP ":(defaultValueType instanceof DateType ?" DATE ":(defaultValueType instanceof TimeType ?" TIME ":"")));
		alterTable += DataTypeFactory.getInstance().fromObject(statement.getDefaultValue(), database).objectToSql(statement.getDefaultValue(), database);
	}

	List<Sql> returnSql = new ArrayList<Sql>();
	returnSql.add(new UnparsedSql(alterTable, new Column().setRelation(new Table().setName(statement.getTableName()).setSchema(new Schema(statement.getCatalogName(), statement.getSchemaName())).setName(statement.getColumnName()))));

	if (statement.isPrimaryKey()) {
		returnSql.addAll(Arrays.asList(SqlGeneratorFactory.getInstance().generateSql(new AddPrimaryKeyStatement(statement.getCatalogName(), statement.getSchemaName(), statement.getTableName(), statement.getColumnName(), null) , database)));
	}

	if (statement.isUnique()) {
		returnSql.addAll(Arrays.asList(SqlGeneratorFactory.getInstance().generateSql(new AddUniqueConstraintStatement(statement.getCatalogName(), statement.getSchemaName(), statement.getTableName(), new ColumnConfig[] { new ColumnConfig().setName(statement.getColumnName())}, null) , database)));
	}
	//	if (statement.getDefaultValue()!=null)
	//		returnSql.addAll(Arrays.asList(SqlGeneratorFactory.getInstance().generateSql(new AddDefaultValueStatement(statement.getSchemaName(), statement.getTableName(), statement.getColumnName(), statement.getColumnType(), statement.getDefaultValue()) , database)));

	addForeignKeyStatements(statement, database, returnSql);

	return returnSql.toArray(new Sql[returnSql.size()]);
}
 

import liquibase.structure.core.Column; //导入依赖的package包/类
@Override
public void run(Namespace namespace, Liquibase liquibase) throws Exception {
    final Set<Class<? extends DatabaseObject>> compareTypes = new HashSet<>();

    if (namespace.getBoolean("columns")) {
        compareTypes.add(Column.class);
    }
    if (namespace.getBoolean("data")) {
        compareTypes.add(Data.class);
    }
    if (namespace.getBoolean("foreign-keys")) {
        compareTypes.add(ForeignKey.class);
    }
    if (namespace.getBoolean("indexes")) {
        compareTypes.add(Index.class);
    }
    if (namespace.getBoolean("primary-keys")) {
        compareTypes.add(PrimaryKey.class);
    }
    if (namespace.getBoolean("sequences")) {
        compareTypes.add(Sequence.class);
    }
    if (namespace.getBoolean("tables")) {
        compareTypes.add(Table.class);
    }
    if (namespace.getBoolean("unique-constraints")) {
        compareTypes.add(UniqueConstraint.class);
    }
    if (namespace.getBoolean("views")) {
        compareTypes.add(View.class);
    }

    final DiffResult diffResult = DiffGeneratorFactory.getInstance().compare(liquibase.getDatabase(), null,
            new CompareControl(compareTypes));
    final DiffToChangeLog diffToChangeLog = new DiffToChangeLog(diffResult, new DiffOutputControl());
    final String filename = namespace.getString("output");

    if (filename != null) {
        try (PrintStream file = new PrintStream(filename, Charsets.UTF_8.name())) {
            diffToChangeLog.print(file);
        }
    } else {
        diffToChangeLog.print(System.out);
    }
}