我正在尝试编写一个过程，但在我的 @qr2 中，当我传递 substring_index() 的参数时，CONCAT 被转义。
知道如何将 '-' 传递到函数中，而不让它转义 CONCAT 函数吗？
我尝试过使用“'-'”或\'-\'，但没有任何效果，它一直在转义。
DELIMITER //
CREATE PROCEDURE filter_bar (IN bar_state VARCHAR(20), done_state VARCHAR(20))
BEGIN
set @qr1 = CONCAT('CREATE TABLE ', done_state, ' like ', bar_state, ';');
PREPARE smt from @qr1;
EXECUTE smt;
DEALLOCATE smt;
set @qr2 = CONCAT('UPDATE ', bar_state, ' SET date = SUBSTRING_INDEX(date,'-',-1);');
PREPARE smt from @qr2;
EXECUTE smt;
DEALLOCATE smt;
set @qr3 = CONCAT('INSERT into', done_state,'select name, business_id, date, sum(count) as count from', bar_state,' group by name, business_id, date;');
PREPARE smt from @qr3;
EXECUTE smt;
END //
最佳答案
您可以使用'':
set @qr2=CONCAT('UPDATE ',bar_state,' SET date=SUBSTRING_INDEX(date,''-'',-1);');
您还需要一个空间:
set @qr3 = CONCAT('INSERT into', done_state,' select name, business_id, date, ...'
-- here
最后:
DEALLOCATE smt;
=>
DEALLOCATE PREPARE smt;
<强> DBFiddle Demo
<小时/>编辑:
为了避免 SQL 注入(inject)问题，您应该用引号将每个出现的标识符括起来:
The quote_identifier() Function
Given a string argument, this function produces a quoted identifier suitable for inclusion in SQL statements. This is useful when a value to be used as an identifier is a reserved word or contains backtick (`) characters.
bar_state
=>
sys.quote_identifier(bar_state)
done_state
=>
sys.quote_identifier(done_state)
关于mysql CONCAT 不断转义，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/52238158/