/*
* Copyright 1999-2015 dangdang.com.
* <p>
* 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.
* </p>
*/
package com.dangdang.ddframe.rdb.sharding.parser.visitor.basic.mysql;
import com.alibaba.druid.sql.ast.expr.SQLVariantRefExpr;
import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlEvalVisitorImpl;
import java.util.Map;
/**
* MySQL变量中提取参数值与编号.
*
* @author gaohongtao
*/
public class MySQLEvalVisitor extends MySqlEvalVisitorImpl {
public static final String EVAL_VAR_INDEX = "EVAL_VAR_INDEX";
@Override
public boolean visit(final SQLVariantRefExpr x) {
if (!"?".equals(x.getName())) {
return false;
}
Map<String, Object> attributes = x.getAttributes();
int varIndex = x.getIndex();
if (varIndex == -1 || getParameters().size() <= varIndex) {
return false;
}
if (attributes.containsKey(EVAL_VALUE)) {
return false;
}
Object value = getParameters().get(varIndex);
if (value == null) {
value = EVAL_VALUE_NULL;
}
attributes.put(EVAL_VALUE, value);
attributes.put(EVAL_VAR_INDEX, varIndex);
return false;
}
}