使用
myQLineEdit.textChanged.connect(
lambda: myQLabel.setStyleSheet("QLabel { color: green}"))
我可以在输入时更改文字颜色。 如果QLineEdit为空，我该如何更改文本颜色？
答案 0 :(得分：1)
SELECT t1.Name, t3.Account, t5.Code
FROM db_table1 AS 1
INNER JOIN db_table2 AS t2 ON t1.Name = t2.Name
INNER JOIN db_table3 AS t3 ON t2.PhoneNum = t3.PhoneNum
INNER JOIN db_table4 AS t4 ON t3.Account = t4.Account
INNER JOIN db_table5 AS t5 ON t4.Zip = t5.Zip
WHERE t2.ID = 16 AND t3.Account = 1234567 AND t5.Code = 'abcd'
UNION
SELECT t1.Name, t3.Account, t5.Code
FROM db_table1 AS 1
INNER JOIN db_table2 AS t2 ON t1.Name = t2.Name
INNER JOIN db_table3 AS t3 ON t2.PhoneNum = t3.PhoneNum
INNER JOIN db_table4 AS t4 ON t3.Account = t4.Account
INNER JOIN db_table5 AS t5 ON t4.Zip = t5.Zip
WHERE t2.ID = 16 AND t3.Account = 2345678 AND t5.Code = 'bcde'
UNION
SELECT t1.Name, t3.Account, t5.Code
FROM db_table1 AS 1
INNER JOIN db_table2 AS t2 ON t1.Name = t2.Name
INNER JOIN db_table3 AS t3 ON t2.PhoneNum = t3.PhoneNum
INNER JOIN db_table4 AS t4 ON t3.Account = t4.Account
INNER JOIN db_table5 AS t5 ON t4.Zip = t5.Zip
WHERE t2.ID = 16 AND t3.Account = 3456789 AND t5.Code = 'cdef'
;
信号将文本作为参数发送，因此您可以使用它来切换颜色：
OR