DescribeStmt.java

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// Copyright 2012 Cloudera Inc.
//
// Licensed 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 com.cloudera.impala.analysis;

import com.cloudera.impala.authorization.Privilege;
import com.cloudera.impala.common.AnalysisException;
import com.cloudera.impala.thrift.TDescribeTableOutputStyle;
import com.cloudera.impala.thrift.TDescribeTableParams;

public class DescribeStmt extends StatementBase {
  private final TDescribeTableOutputStyle outputStyle_;
  private TableName tableName_;

  public DescribeStmt(TableName tableName, TDescribeTableOutputStyle outputStyle) {
    this.tableName_ = tableName;
    this.outputStyle_ = outputStyle;
  }

  @Override
  public String toSql() {
    StringBuilder sb = new StringBuilder("DESCRIBE ");
    if (outputStyle_ != TDescribeTableOutputStyle.MINIMAL) {
      sb.append(outputStyle_.toString());
    }
    return sb.toString() + tableName_;
  }

  public TableName getTable() { return tableName_; }
  public TDescribeTableOutputStyle getOutputStyle() { return outputStyle_; }

  @Override
  public void analyze(Analyzer analyzer) throws AnalysisException {
    if (!tableName_.isFullyQualified()) {
      tableName_ = new TableName(analyzer.getDefaultDb(), tableName_.getTbl());
    }
    analyzer.getTable(tableName_, Privilege.VIEW_METADATA);
  }

  public TDescribeTableParams toThrift() {
    TDescribeTableParams params = new TDescribeTableParams();
    params.setTable_name(getTable().getTbl());
    params.setDb(getTable().getDb());
    params.setOutput_style(outputStyle_);
    return params;
  }
}