graphical sql query builder

">SELECT* FROM book WHERE bookname like'%${value}%'Select>--> can prevent SQL injectionSelectId="Likeselect"Parametertype="string"Resulttype=" Book">SELECT* FROM book WHERE bookname like'%'#{value}'%'Select>--> SelectId="Likeselect"Parametertype="string"Resulttype=" Book">SELECT"MySQL"/> from book WHERE bookname like Concat ('%', #{bookname},'%') Select>　　Three ways, the first is not to prevent SQL injec

DEPT D WHERE D.DEPT_NO = E.DEPT_NO AND DEPT_CAT = 'A'); Of course, the most efficient way is to associate tables. directly link two tables with the fastest speed! 11. Identify 'inefficient execution' SQL statements Use the following SQL tools to find out inefficient SQL statements: SELECT EXECUTIONS , DISK_READS, BUFFER_GETS, ROUND((B

improve efficiency. Rewrite as: (Method one: efficient) SELECT ... from EMP a,dept B WHERE a.dept_no = b.dept (+) and B.dept_no is NULL and b.dept_cat (+) = ' A ' (Method two: most efficient) Select ... from EMP E where not EXISTS (select ' X ' from DEPT D where d.dept_no = E.dept_no and dept_ CAT = ' A '); Of course, the most efficient way is to have a table association. Direct two-table relationship couplet speed is the

things to do all kinds of optimization, have not been how to improve Later, for the second way, the physical table is treated like this: use Column2 and #t共同去过滤TableA, wait until an intermediate result set, and then go to drive the other table Generated graphical execution plan, estimated two screens are not displayed, through step by step observation, looked for a long time, only to find that this difference, Although the final result is the same, b

650) this.width=650; "Src=" http://images2017.cnblogs.com/blog/139239/201709/139239-20170905092130538-711765515. JPG "width=" 407 "height=" 226 "style=" border:0px; "/>In the previous article, we learned how SQL queries are executed and what you need to be aware of when writing SQL query statements.Below, I further study the