/**
* 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.drill.exec.planner.sql.parser;
import java.util.List;
import net.hydromatic.optiq.tools.Planner;
import org.apache.drill.exec.ops.QueryContext;
import org.apache.drill.exec.planner.sql.handlers.AbstractSqlHandler;
import org.apache.drill.exec.planner.sql.handlers.DescribeTableHandler;
import org.eigenbase.sql.SqlCall;
import org.eigenbase.sql.SqlIdentifier;
import org.eigenbase.sql.SqlKind;
import org.eigenbase.sql.SqlLiteral;
import org.eigenbase.sql.SqlNode;
import org.eigenbase.sql.SqlOperator;
import org.eigenbase.sql.SqlSpecialOperator;
import org.eigenbase.sql.SqlWriter;
import org.eigenbase.sql.parser.SqlParserPos;
import com.google.common.collect.Lists;
/**
* Sql parser tree node to represent statement:
* { DESCRIBE | DESC } tblname [col_name | wildcard ]
*/
public class SqlDescribeTable extends DrillSqlCall {
private final SqlIdentifier table;
private final SqlIdentifier column;
private final SqlNode columnQualifier;
public static final SqlSpecialOperator OPERATOR =
new SqlSpecialOperator("DESCRIBE_TABLE", SqlKind.OTHER){
public SqlCall createCall(SqlLiteral functionQualifier, SqlParserPos pos, SqlNode... operands) {
return new SqlDescribeTable(pos, (SqlIdentifier) operands[0], (SqlIdentifier) operands[1], operands[2]);
}
};
public SqlDescribeTable(SqlParserPos pos, SqlIdentifier table, SqlIdentifier column, SqlNode columnQualifier) {
super(pos);
this.table = table;
this.column = column;
this.columnQualifier = columnQualifier;
}
@Override
public SqlOperator getOperator() {
return OPERATOR;
}
@Override
public List<SqlNode> getOperandList() {
List<SqlNode> opList = Lists.newArrayList();
opList.add(table);
opList.add(column);
opList.add(columnQualifier);
return opList;
}
@Override
public void unparse(SqlWriter writer, int leftPrec, int rightPrec) {
writer.keyword("DESCRIBE");
writer.keyword("TABLE");
table.unparse(writer, leftPrec, rightPrec);
if (column != null) column.unparse(writer, leftPrec, rightPrec);
if (columnQualifier != null) columnQualifier.unparse(writer, leftPrec, rightPrec);
}
@Override
public AbstractSqlHandler getSqlHandler(Planner planner, QueryContext context) {
return new DescribeTableHandler(planner, context);
}
public SqlIdentifier getTable() { return table; }
public SqlIdentifier getColumn() { return column; }
public SqlNode getColumnQualifier() { return columnQualifier; }
}