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druid的SQLParser解析HQL语句


让druid的SQLParser解析HQL语句,生成SELECT ......FROM.....WHERE ......的形式,闲话少说,直接上例子:

package com.alibaba.druid;

import java.util.List;
import com.alibaba.druid.sql.SQLUtils;
import com.alibaba.druid.sql.ast.SQLExpr;
import com.alibaba.druid.sql.ast.SQLStatement;
import com.alibaba.druid.sql.ast.statement.SQLSelect;
import com.alibaba.druid.sql.ast.statement.SQLSelectItem;
import com.alibaba.druid.sql.ast.statement.SQLSelectQuery;
import com.alibaba.druid.sql.ast.statement.SQLSelectQueryBlock;
import com.alibaba.druid.sql.ast.statement.SQLSelectStatement;
import com.alibaba.druid.sql.parser.SQLExprParser;
import com.alibaba.druid.sql.parser.SQLParserUtils;
import com.alibaba.druid.sql.parser.SQLSelectParser;
import com.alibaba.druid.sql.parser.SQLStatementParser;
import com.alibaba.druid.sql.visitor.SQLASTOutputVisitor;
import com.alibaba.druid.util.JdbcUtils;

public class ParseTest {

public ParseTest() {
// TODO Auto-generated constructor stub
}

public static void main(String[] args){

String sql ="select p, s.count as views, (select count(*) from Comments rc where rc.linkedId=p.id and rc.classcode='InfoPublishs') as commentNumber, (select count(*) from CollectIndexs rci where rci.toId=p.id and rci.classcode='InfoPublishs' and rci.type='favorite') as favorite FROM InfoPublishs p,UserScores s where p.id=s.linkedId and p.userInfo.id=s.userInfo.id and s.classCode='InfoPublishs' AND p.status=?1 ORDER BY p.createtime DESC";

StringBuffer select = new StringBuffer();
StringBuffer from = new StringBuffer();
StringBuffer where = new StringBuffer();

// parser得到AST
SQLStatementParser parser = SQLParserUtils.createSQLStatementParser(sql, JdbcUtils.MYSQL);
List stmtList = parser.parseStatementList(); //

// 将AST通过visitor输出
SQLASTOutputVisitor visitor = SQLUtils.createFormatOutputVisitor(from, stmtList, JdbcUtils.MYSQL);
SQLASTOutputVisitor whereVisitor = SQLUtils.createFormatOutputVisitor(where, stmtList, JdbcUtils.MYSQL);

for (SQLStatement stmt : stmtList) {
// stmt.accept(visitor);
if(stmt instanceof SQLSelectStatement){
SQLSelectStatement sstmt = (SQLSelectStatement)stmt;
SQLSelect sqlselect = sstmt.getSelect();
SQLSelectQueryBlock query = (SQLSelectQueryBlock)sqlselect.getQuery();

query.getFrom().accept(visitor);
query.getWhere().accept(whereVisitor);
}
}

System.out.println(from.toString());
System.out.println(select);
System.out.println(where);
}
}



输出结果是:



InfoPublishs p, UserScores s




p.id = s.linkedId


AND p.userInfo.id = s.userInfo.id


AND s.classCode = 'InfoPublishs'


AND p.status = ?1



大家觉得怎么样呢?觉的有用就收着吧,没用就扔了。




上面例子有些问题, 不知道是版本还是什么原因,


下面这个例子, 如果真的要实用, 还得修改


public static void sqlDecomposition(String query,boolean isPrefix) throws InterruptedException {
//Map<String,AnalysisPool> apMap=new HashMap<String,AnalysisPool>();
StringBuffer from=new StringBuffer();
SQLStatementParser parser=SQLParserUtils.createSQLStatementParser(query,JdbcUtils.HIVE);
List<SQLStatement> stmtList=parser.parseStatementList();
SQLASTOutputVisitor visitor=SQLUtils.createFormatOutputVisitor(from,stmtList,JdbcUtils.HIVE);
List<SQLSelectItem> sL=new ArrayList<SQLSelectItem>();
SQLStatement stmt=stmtList.iterator().next();
SQLSelectStatement sstmt=(SQLSelectStatement)stmt;
SQLSelect sqlselect=sstmt.getSelect();
SQLSelectQueryBlock sqb=(SQLSelectQueryBlock)sqlselect.getQuery();
SQLTableSource fromx=sqb.getFrom();
fromx.accept(visitor);
sL=sqb.getSelectList();
StringBuffer sb=new StringBuffer();
for ( SQLSelectItem sqi : sL) {
if (sqi.getExpr() instanceof SQLCaseExpr) {
sb.append(sqi.getAlias()).append(",");
}
else {
sb.append(sqi.toString()).append(",");
}
}
System.out.println("* ???? : " + sb.toString().substring(0, sb.toString().length() - 1));
//sourceAnalysis(fromx,apMap);
}

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