Java （JDBC）带if语句和多条件的Mysql查询

像这样的mysql java语句的正确语法是什么

PreparedStatement st =connection.prepareStatement("SELECT Name, Value, Quantity FROM sales if (type=='Purchase' AND state=='confirmed') OR (type=='Sale' AND state=='not confirmed'))  ; 

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SQL将如下所示：

SELECT Name, Value, Quantity
FROM sales 
WHERE (type = 'Purchase' AND state = 'confirmed') OR
      (type = 'Sale' AND state = 'not confirmed');

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条件应该在

where子句中，而不是
if
子句中，并且SQL中的等式检查运算符是
=
，而不是
=`。因此：

SELECT Name, Value, Quantity 
FROM   sales 
WHERe  (type = 'Purchase' AND state = 'confirmed') OR 
       (type = 'Sale' AND state = 'not confirmed')