statementType statement、preparedstatement、callablestatement。预准备语句、可调用语句 STATEMENT、PREPARED、CALLABLE PREPARED 批量更新 情景一:更新多条记录为多个字段为不同的值 方法一: 1<update id="updateBatch"parameterType="java.util.List">2<foreachcollection="list"item="item"index="index"open=""close="...
比如,动态SQL中的字段名,如:ORDER BY ${columnName} <select id="queryMetaList" resultType="Map" statementType="STATEMENT"> Select * from emp where name = ${employeeName} ORDER BY ${columnName} </select> 由于${}仅仅是简单的取值,所以以前sql注入的方法适用此处,如果我们order by语句后用了${},...
<selectid="querypersonbyname"parameterType="String"resultType="com.test.Person"> select * from person where name like "%${value}%" </select> mysql数据库:like CONCAT('%',#{name},'%') 这里是使用CONCAT进行拼接,name可以为其他名字 <selectid="querypersonbyname"parameterType="String"resultType="c...
public <E> List<E> selectList(String statement, Object parameter, RowBounds rowBounds) { try { // 通过MappedStatement的Id获取 MappedStatement MappedStatement ms = configuration.getMappedStatement(statement); // 调用 Executor 实现类中的 query 方法 return executor.query(ms, wrapCollection(parameter), ...
();// 创建 StatementHandlerStatementHandlerhandler=configuration.newStatementHandler(wrapper,ms,parameter,rowBounds,resultHandler,boundSql);// 创建 Statementstmt=prepareStatement(handler,ms.getStatementLog());// 执行查询操作returnhandler.<E>query(stmt,resultHandler);}finally{// 关闭 StatementcloseStatement(...
Query plan 优化,包含在无统计信息时的优化和基于 rollup 的统计信息的优化。 修复MySQL catalog 中 to_date 函数下推的问题。 优化JDBC 客户端连接关闭的逻辑,在异常时正常取消查询。 优化routine load 的内存占用和错误信息。 Enterprise Core 2.0.4
avoid insertion of duplicate entries in a BULK INSERT statement Bad performance of EXCEPT operator Basic - select with fixed values - invert columns to rows Basic CTE query, get full path of something recursive BCP Error - Copy direction must be either 'in', 'out' or 'format'. BCP Export...
通常情况下,一条 SQL 语句的执行需要经过三个步骤:首先通过 SQL Parser 解析语句,生成抽象语法树(AST),随后通过 Query Optimizer 生成可执行计划(Plan),最终通过执行该计划得到计算结果。对于大数据量下的复杂查询,经由查询优化器生成的执行计划无疑具有更高效的执行效果,但对于低延时和高并发要求的点查询,则不适宜走...
Statement dependency system The SELECT depends on all the tables and views named in the query and the conglomerates (units of storage such as heaps and indexes) chosen for access paths on those tables. CREATE INDEX does not invalidate a prepared SELECT statement. A DROP INDEX statement invalidate...
nt.java:1075) at oracle.jdbc.driver.OraclePreparedStatement.executeInternal(OraclePrep aredStatement.java:3820) at oracle.jdbc.driver.OraclePreparedStatement.execute(OraclePreparedStat ement.java:3923) Atul_Rai Posted on March 04, 2015 You have enter a wrong SQL query. To insert the data in table...