当然有变化col_a = 'a' and col_b = 'b' and col_c = 'c' or col_d = 'd' and col_e = 'e' or col_f = 'f'……
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(col_a = 'a' and col_b = 'b' and col_c = 'c') or (col_d = 'd' and col_e = 'e') or (col_f = 'f'……)col_a = 'a' and col_b = 'b' or col_d = 'd' and col_c = 'c' and col_e = 'e' or col_f = 'f'…… ---d,c换了
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(col_a = 'a' and col_b = 'b' ) or (col_d = 'd' and col_c = 'c' and col_e = 'e') or (col_f = 'f'……)
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(col_a = 'a' and col_b = 'b' and col_c = 'c') or (col_d = 'd' and col_e = 'e') or (col_f = 'f'……)col_a = 'a' and col_b = 'b' or col_d = 'd' and col_c = 'c' and col_e = 'e' or col_f = 'f'…… ---d,c换了
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(col_a = 'a' and col_b = 'b' ) or (col_d = 'd' and col_c = 'c' and col_e = 'e') or (col_f = 'f'……)
可以使用括号来执行先后的顺序。