content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.apache.ambari.server.orm.helpers.dbms;
  
  import org.apache.ambari.server.orm.DBAccessor;
  import org.eclipse.persistence.platform.database.DatabasePlatform;
  
  public class PostgresHelper extends GenericDbmsHelper {
    public PostgresHelper(DatabasePlatform databasePlatform) {
      super(databasePlatform);
    }
  
    @Override
    public boolean supportsColumnTypeChange() {
      return true;
    }
  
    @Override
    public StringBuilder writeColumnRenameString(StringBuilder builder, String oldName, DBAccessor.DBColumnInfo newColumnInfo) {
      builder.append(" RENAME COLUMN ").append(oldName).append(" TO ").append(newColumnInfo.getName());
      return builder;
    }
  
    @Override
    public StringBuilder writeColumnModifyString(StringBuilder builder, DBAccessor.DBColumnInfo columnInfo) {
      builder.append(" ALTER COLUMN ").append(columnInfo.getName()).append(" TYPE ");
      writeColumnType(builder, columnInfo);
      return builder;
    }
  
    /**
     {@inheritDoc}
     */
    @Override
    public String getCopyColumnToAnotherTableStatement(String sourceTable, String sourceColumnName,
           String sourceIDColumnName, String targetTable, String targetColumnName, String targetIDColumnName) {
  
      return String.format("UPDATE %1$s AS a SET %3$s = b.%4$s FROM %2$s AS b WHERE a.%5$s = b.%6$s",
        targetTable, sourceTable, targetColumnName, sourceColumnName, targetIDColumnName, sourceIDColumnName);
    }
  
    /**
     * {@inheritDoc}
     */
    @Override
    public String getCopyColumnToAnotherTableStatement(String sourceTable, String sourceColumnName,
                                                       String sourceIDColumnName1, String sourceIDColumnName2,
                                                       String sourceIDColumnName3,
                                                       String targetTable, String targetColumnName,
                                                       String targetIDColumnName1, String targetIDColumnName2,
                                                       String targetIDColumnName3,
                                                       String sourceConditionFieldName, String condition) {
      return String.format("UPDATE %1$s AS a SET %3$s = b.%4$s FROM %2$s AS b WHERE a.%5$s = b.%8$s AND a.%6$s = b.%9$s AND a.%7$s = b.%10$s AND b.%11$s = '%12$s'",
          targetTable, sourceTable, targetColumnName, sourceColumnName, targetIDColumnName1, targetIDColumnName2, targetIDColumnName3,
          sourceIDColumnName1, sourceIDColumnName2, sourceIDColumnName3, sourceConditionFieldName, condition);
    }
  
    @Override
    public StringBuilder writeSetNullableString(StringBuilder builder,
        String tableName, DBAccessor.DBColumnInfo columnInfo, boolean nullable) {
      builder.append(" ALTER COLUMN ").append(columnInfo.getName());
      String nullStatement = nullable ? " DROP NOT NULL" : " SET NOT NULL";
      builder.append(nullStatement);
      return builder;
    }
  
    @Override
    public String writeGetTableConstraints(String databaseName, String tableName) {
      // pg_class: http://www.postgresql.org/docs/9.4/static/catalog-pg-class.html
      // pg_constraint: http://www.postgresql.org/docs/9.4/static/catalog-pg-constraint.html
      // pg_namespace: http://www.postgresql.org/docs/9.4/static/catalog-pg-namespace.html
      StringBuilder statement = new StringBuilder()
        .append("SELECT ")
          .append("c.conname as CONSTRAINT_NAME,")
          .append("c.contype as CONSTRAINT_TYPE ")
        .append("FROM pg_catalog.pg_constraint as c ")
        .append("JOIN pg_catalog.pg_namespace as namespace ")
          .append("on namespace.oid = c.connamespace ")
        .append("JOIN pg_catalog.pg_class as class ")
          .append("on class.oid = c.conrelid ")
        .append("where (namespace.nspname='").append(databaseName).append("' or namespace.nspname='public')")
        .append("and class.relname='").append(tableName).append("'");
  
      return statement.toString();
    }
  
    @Override
    public  StringBuilder writeDropPrimaryKeyStatement(StringBuilder builder, String constraintName, boolean cascade){
        return builder.append("DROP CONSTRAINT ").append(constraintName).append(cascade ? " CASCADE" : "");
    }
  }
  