package liquibase.sqlgenerator.core;
import liquibase.datatype.DataTypeFactory;
import liquibase.exception.Warnings;
import liquibase.sqlgenerator.SqlGeneratorChain;
import liquibase.statement.core.ModifyDataTypeStatement;
import liquibase.database.Database;
import liquibase.database.core.*;
import liquibase.exception.ValidationErrors;
import liquibase.sql.Sql;
import liquibase.sql.UnparsedSql;
import liquibase.structure.core.Relation;
import liquibase.structure.core.Table;
public class ModifyDataTypeGenerator extends AbstractSqlGenerator<ModifyDataTypeStatement> {
@Override
public boolean supports(ModifyDataTypeStatement statement, Database database) {
if (database instanceof SQLiteDatabase) {
return false;
}
return super.supports(statement, database);
}
@Override
public Warnings warn(ModifyDataTypeStatement modifyDataTypeStatement, Database database, SqlGeneratorChain sqlGeneratorChain) {
Warnings warnings = super.warn(modifyDataTypeStatement, database, sqlGeneratorChain);
if (database instanceof MySQLDatabase && !modifyDataTypeStatement.getNewDataType().toLowerCase().contains("varchar")) {
warnings.addWarning("modifyDataType will lose primary key/autoincrement/not null settings for mysql. Use <sql> and re-specify all configuration if this is the case");
}
return warnings;
}
@Override
public ValidationErrors validate(ModifyDataTypeStatement statement, Database database, SqlGeneratorChain sqlGeneratorChain) {
ValidationErrors validationErrors = new ValidationErrors();
validationErrors.checkRequiredField("tableName", statement.getTableName());
validationErrors.checkRequiredField("columnName", statement.getColumnName());
validationErrors.checkRequiredField("newDataType", statement.getNewDataType());
return validationErrors;
}
@Override
public Sql[] generateSql(ModifyDataTypeStatement statement, Database database, SqlGeneratorChain sqlGeneratorChain) {
String alterTable = "ALTER TABLE " + database.escapeTableName(statement.getCatalogName(), statement.getSchemaName(), statement.getTableName());
// add "MODIFY"
alterTable += " " + getModifyString(database) + " ";
// add column name
String columnName = database.escapeColumnName(statement.getCatalogName(), statement.getSchemaName(), statement.getTableName(), statement.getColumnName());
alterTable += columnName;
alterTable += getPreDataTypeString(database); // adds a space if nothing else
// add column type
alterTable += DataTypeFactory.getInstance().fromDescription(statement.getNewDataType(), database).toDatabaseDataType(database);
if (database instanceof PostgresDatabase) {
alterTable += " USING ("+columnName+"::"+statement.getNewDataType()+")";
}
return new Sql[]{new UnparsedSql(alterTable, getAffectedTable(statement))};
}
protected Relation getAffectedTable(ModifyDataTypeStatement statement) {
return new Table().setName(statement.getTableName()).setSchema(statement.getCatalogName(), statement.getSchemaName());
}
/**
* @return either "MODIFY" or "ALTER COLUMN" depending on the current db
*/
protected String getModifyString(Database database) {
if (database instanceof SybaseASADatabase
|| database instanceof SybaseDatabase
|| database instanceof MySQLDatabase
|| database instanceof OracleDatabase
|| database instanceof InformixDatabase
) {
return "MODIFY";
} else {
return "ALTER COLUMN";
}
}
/**
* @return the string that comes before the column type
* definition (like 'set data type' for derby or an open parentheses for Oracle)
*/
protected String getPreDataTypeString(Database database) {
if (database instanceof DerbyDatabase
|| database instanceof DB2Database) {
return " SET DATA TYPE ";
} else if (database instanceof SybaseASADatabase
|| database instanceof SybaseDatabase
|| database instanceof MSSQLDatabase
|| database instanceof MySQLDatabase
|| database instanceof HsqlDatabase
|| database instanceof H2Database
|| database instanceof OracleDatabase
|| database instanceof InformixDatabase) {
return " ";
} else {
return " TYPE ";
}
}
}