com.cloudera.impala.analysis.AlterTableStmt.java Source code

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Here is the source code for com.cloudera.impala.analysis.AlterTableStmt.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.catalog.DataSourceTable;
import com.cloudera.impala.catalog.Table;
import com.cloudera.impala.catalog.View;
import com.cloudera.impala.common.AnalysisException;
import com.cloudera.impala.thrift.TAlterTableParams;
import com.cloudera.impala.thrift.TTableName;
import com.google.common.base.Preconditions;

/**
 * Base class for all ALTER TABLE statements.
 */
public abstract class AlterTableStmt extends StatementBase {
    protected final TableName tableName_;

    // Set during analysis.
    protected Table table_;

    protected AlterTableStmt(TableName tableName) {
        Preconditions.checkState(tableName != null && !tableName.isEmpty());
        tableName_ = tableName;
        table_ = null;
    }

    public String getTbl() {
        return tableName_.getTbl();
    }

    /**
     * Can only be called after analysis, returns the parent database name of the target
     * table for this ALTER TABLE statement.
     */
    public String getDb() {
        return getTargetTable().getDb().getName();
    }

    /**
     * Can only be called after analysis, returns the Table object of the target of this
     * ALTER TABLE statement.
     */
    protected Table getTargetTable() {
        Preconditions.checkNotNull(table_);
        return table_;
    }

    public TAlterTableParams toThrift() {
        TAlterTableParams params = new TAlterTableParams();
        params.setTable_name(new TTableName(getDb(), getTbl()));
        return params;
    }

    @Override
    public void analyze(Analyzer analyzer) throws AnalysisException {
        table_ = analyzer.getTable(tableName_, Privilege.ALTER);
        if (table_ instanceof View) {
            throw new AnalysisException(
                    String.format("ALTER TABLE not allowed on a view: %s", table_.getFullName()));
        }
        if (table_ instanceof DataSourceTable) {
            throw new AnalysisException(String.format(
                    "ALTER TABLE not allowed on a table produced by a data source: %s", table_.getFullName()));
        }
    }
}