Sql statement splicing mainly involves conditional addition, deletion, modification or query. The following is an example of a conditional query:

Because the length of the spliced sql statement is uncertain, it is decorated with StringBuffer instead of String.

string name = request . getparameter(" name ")；

string address = request . getparemeter(" address ")；

string buffer SQL = new string buffer()；

SQL . append(" select * from Tuser as t where 1 = 1 ")；

If (name! =null||！ "".Equal to (name)) {

Sql.append ("and t.namelike"% "+name+"%");

}

If (address! =null||！ "".Equal to (address)) {

Sql.append ("and t.addresslike"% "+address+"%");

}

The above is a concatenated sql statement, which means select * from Tuser as, where 1 = 1 will definitely be executed, and the last two will be executed according to user data parameters.

I wrote it by hand, not copied it, okay? Ask me if you don't know, and give points if you understand, hehe.