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java 使用JSqlParser和CCJSqlParser 解析sql

news 2025/7/12 20:07:27

maven

<dependency><groupId>com.github.jsqlparser</groupId><artifactId>jsqlparser</artifactId><version>4.9</version>
</dependency>

解析SQL

String sql = "select aa,bb from b";
Statement statement=CCJSqlParserUtil.parse(sql)；
Select selectStatement = (Select) statement;
PlainSelect plainSelect = selectStatement.getPlainSelect();
//plainSelect可以获取sql各个部分 如属性集合
List<SelectItem<?>> selectItems0 = plainSelect.getSelectItems();

分析
Statement 被设计成一个接口满足CURD各个处理方式
1、查询PlainSelect继承Select

        1.1//字段起别名  SELECT aa AS ALIAS1, bb AS ALIAS2 FROM bAddAliasesVisitor instance = new AddAliasesVisitor();instance.setPrefix("alias");selectStatement.accept(instance);1.2//加字段SELECT aa AS ALIAS1, bb AS ALIAS2, field FROM bSelectUtils.addExpression(selectStatement, new Column("field"));1.3//加字段表达式 SELECT aa AS ALIAS1, bb AS ALIAS2, field, 5 + 6 FROM bAddition add = new Addition();add.setLeftExpression(new LongValue(5));add.setRightExpression(new LongValue(6));SelectUtils.addExpression(selectStatement, add);1.4//加join  //SELECT aa AS ALIAS1, bb AS ALIAS2, field, 5 + 6 FROM b LEFT JOIN mytable2 ON a = bEqualsTo equalsTo = new EqualsTo();Statement select = (PlainSelect) test(sql);equalsTo.setLeftExpression(new Column("a"));equalsTo.setRightExpression(new Column("b"));Join addJoin = SelectUtils.addJoin(selectStatement, new Table("mytable2"), equalsTo);addJoin.setLeft(true);//SelectUtils构建一个SQL语句Select selectbuild = SelectUtils.buildSelectFromTableAndExpressions(new Table("mytable"), new Column("a"), new Column("b"));//SELECT a, b, c FROM mytableSelectUtils.addExpression(selectbuild, new Column("c"));//where 条件设置EqualsTo equalsTo1 = new EqualsTo();equalsTo1.setLeftExpression(new Column("id"));equalsTo1.setRightExpression(new Column("1"));PlainSelect plainSelect1 = selectbuild.getPlainSelect();plainSelect1.setWhere(equalsTo1);更多条件访问 https://blog.csdn.net/a250152/article/details/128610616