StmtDropIndex.java :  » Database-DBMS » Quadcap-Embeddable-Database » com » quadcap » sql » Java Open Source

package com.quadcap.sql;

/* Copyright 1999 - 2003 Quadcap Software.  All rights reserved.
 *
 * This software is distributed under the Quadcap Free Software License.
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import java.util.Vector;

import java.io.IOException;

import java.sql.SQLException;

import com.quadcap.util.Debug;

/**
 * Implementation of the SQL <b>DROP INDEX</b> statement. 
 *
 * @author Stan Bailes
 */

public class StmtDropIndex implements Stmt {
    String    indexName;

    public StmtDropIndex() {}
    
    public StmtDropIndex(String indexName) {
  this.indexName = indexName;
    }

    public void execute(Session session) throws IOException, SQLException {
        session.getTableWriteLock("#Schema");
  Database db = session.getDatabase();
  String tableName = db.getTableForIndex(indexName);
  if (tableName == null) {
      throw new SQLException("No such index: " + indexName);
  }
        session.getTableWriteLock(tableName);
  Table t = (Table)db.getRelation(tableName);
  if (t == null) {
      throw new SQLException("No table: " + tableName + " for index " +
           indexName);
  }
  Constraint c = t.getConstraint(indexName);
  if (c == null) {
      throw new SQLException("Can't find constraint associated with " +
           "index " + indexName + " for table " +
           tableName);
  }
  session.doStep(new DeleteConstraint(session, t, c, true));
    }
}