[英]LEFT OUTER JOIN with a WHERE clause on the first table
I want to SELECT
a some rows from a table, but these rows must satisfy a condition like column = value
. 我想从表中SELECT
一些行,但是这些行必须满足诸如column = value
的条件。 Here's my SELECT
statement: 这是我的SELECT
语句:
$query = "SELECT t1.title, t1.introtext, t2.jr_street, t2.jr_city,
t2.jr_state, t2.jr_postalcode, t2.jr_country, t3.created, t3.name,
t3.title, t3.comments, t4.ave
FROM $table1 t1
LEFT OUTER JOIN $table2 t2 ON t1.id = t2.contentid
LEFT OUTER JOIN $table3 t3 ON t1.id = t3.pid
LEFT OUTER JOIN $table4 t4 ON t1.id = t4.reviewid
";
I tried adding a WHERE
clause after the FROM
statement, but I am getting an SQL syntax error. 我尝试在FROM
语句后添加WHERE
子句,但出现SQL语法错误。
Seems like I have to guess your problem. 好像我不得不猜测你的问题。 Next time you should give us your full example a the exact error. 下次您应该给我们提供完整示例的确切错误。 Did you try something like this? 你尝试过这样的事情吗?
$value = (int) $_POST['value'];
$query = "SELECT t1.title, t1.introtext, t2.jr_street, t2.jr_city, t2.jr_state,
t2.jr_postalcode, t2.jr_country, t3.created, t3.name, t3.title,
t3.comments, t4.ave FROM $table1 t1
LEFT OUTER JOIN $table2 t2 ON t1.id = t2.contentid
LEFT OUTER JOIN $table3 t3 ON t1.id = t3.pid
LEFT OUTER JOIN $table4 t4 ON t1.id = t4.reviewid
WHERE t2.column = ".$value."
AND t1.catid=8";
I just guessed you want to select from table2 ;) You have to fill in the right table and column. 我只是猜测您要从table2中选择;)您必须填写正确的表和列。 Also i put the category selection in the where clause since imho this makes it more readable. 我也将类别选择放在where子句中,因为恕我直言,这使它更具可读性。
Please make absolutely sure that all variables like $value
(and the tables) are save for usage in a query, for example that $value
is an integer and the tables are explicitly set in your code and are not a user input. 请绝对确保将所有变量(如$value
(和表))保存下来以在查询中使用,例如, $value
是整数,并且表已在您的代码中显式设置,而不是用户输入。 You can read more about SQL-Injections here: 您可以在此处阅读有关SQL注入的更多信息:
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