What does where 1=1 mean in the sql statement?
where 1=1 should be automatically generated by a program (such as Java). The conditions after 1=1 in the where condition are dynamically changed through the if block. For example:
String sql="select * from table_name where 1=1";
if( conditon 1) {
sql=sql+" and var2=value2";
}
if(conditon 2) {
sql=sql+" and var3=value3";
}where 1=1 is to avoid grammatical errors caused by the first word after the where keyword being directly "and".
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