Today, my colleague asked me a question. According to the sql parameters passed in, we need to determine which filter conditions to use. I thought it could be solved by using the <if></if> tags directly. Then I found that the old system no longer has documents. Without this if tag, there is only a non-empty <nnv></nnv> tag,
So how can we achieve the effect of if branching?
On a whim, select 1 as a from dual where ('param'='1' and 《Your Filter Condition 1》) or ('param'='2' and 《Your Filter Condition 2》)
Achieving the effect of the if branch