functions.py 文件源码

def compile_sqlite_sign(element, compiler, **kw):
    args = list(element.clauses)
    if len(args) != 1:
        raise CompileError("Sign function takes exactly one argument.")
    return (
        "CASE WHEN {0} < 0 THEN -1 "
        "ELSE CASE WHEN {0} > 0 THEN 1 "
        "ELSE 0 END END".format(
            compiler.process(args[0])
        )
    )