ShowTablesStmt.java

Go to the documentation of this file.

// 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.TShowTablesParams;
import com.google.common.base.Preconditions;

public class ShowTablesStmt extends StatementBase {
  // Pattern to match tables against. | denotes choice, * matches all strings
  private final String pattern_;

  // DB (if any) as seen by the parser
  private final String parsedDb_;

  // Set during analysis
  private String postAnalysisDb_;

  public ShowTablesStmt() {
    this(null, null);
  }

  public ShowTablesStmt(String pattern) {
    this(null, pattern);
  }

  public ShowTablesStmt(String database, String pattern) {
    this.parsedDb_ = database;
    this.pattern_ = pattern;
    this.postAnalysisDb_ = null;
  }

  public String getPattern() { return pattern_; }

  public String getDb() {
    Preconditions.checkNotNull(postAnalysisDb_);
    return postAnalysisDb_;
  }

  @Override
  public String toSql() {
    if (pattern_ == null) {
      if (parsedDb_ == null) {
        return "SHOW TABLES";
      } else {
        return "SHOW TABLES IN " + parsedDb_;
      }
    } else {
      if (parsedDb_ == null) {
        return "SHOW TABLES LIKE '" + pattern_ + "'";
      } else {
        return "SHOW TABLES IN " + parsedDb_ + " LIKE '" + pattern_ + "'";
      }
    }
  }

  @Override
  public void analyze(Analyzer analyzer) throws AnalysisException {
    postAnalysisDb_ = (parsedDb_ == null ? analyzer.getDefaultDb() : parsedDb_);
    if (analyzer.getDb(postAnalysisDb_, Privilege.ANY) == null) {
      throw new AnalysisException(Analyzer.DB_DOES_NOT_EXIST_ERROR_MSG + postAnalysisDb_);
    }
  }

  public TShowTablesParams toThrift() {
    TShowTablesParams params = new TShowTablesParams();
    params.setShow_pattern(getPattern());
    params.setDb(getDb());
    return params;
  }
}