Oracle I don't understand the 'A'='A' and 'A'='B' this kind of writing, what is consciousness?
I run after the result is to select * from t the where (tc ode='A' or tc ode='B'),
That why do you write (tc ode='A' or tc ode='B') and 'A'='A' or tc ode<> 'A' and tc ode<> 'B' and 'A'='B',
I used to use is the MSSQL database, use oracle now after see this is written statements don't know why,
Please answer, thank you very much,
CodePudding user response:
This kind of writing is rarely a=a condition is true, a=b is the condition is false, I wrote before the Oracle, also not so written, anyhow is not common, need not too entanglements