Iyo SQL DELETE
chirevo chinoshandiswa kudzima zvinyorwa kubva patafura nepo DROP
chirevo chinoshandiswa kudzima tafura kana dhatabhesi.
I TRUNCATE TABLE
chirevo chinogona kushandiswa kudzima zvinyorwa kubva patafura.
I DELETE
chirevo muSQL chinoshandiswa kudzima zvinyorwa kubva patafura ye database. Tinogona kubvisa zvese zvinyorwa kubva patafura kana kudzima chaiwo marekodhi tichishandisa WHERE chirevo.
DELETE FROM table_name WHERE condition;
Ngatifungei kuti tine tafura inonzi 'Vashandi' ine zvinyorwa zvinotevera:
+------------+-----------+----------+------------+ | EmployeeID | FirstName | LastName | Department | +------------+-----------+----------+------------+ | 1
| Mark
| Otto
| Finance | | 2
| Jacob
| Thornton | IT
| | 3
| Su
| Bird
| Marketing | | 4
| Sam
| Burger | IT
| +------------+-----------+----------+------------+
Iyi inotevera kodhi inobvisa 'Jacob Thornton' kubva kune 'Vashandi' tafura:
DELETE FROM Employees WHERE FirstName = 'Jacob' AND LastName = 'Thornton';
Ongorora:Mumuenzaniso wepamusoro, tinoshandisa mamiriro maviri, KUPI uye Uye , kureva zita rekutanga uye zita rokupedzisa. Izvi ndezvekuona kuti tinodzima rekodhi chaiyo, kana paine mumwe mushandi ane zita rekutanga.Iyi inotevera kodhi inobvisa zvese zvinyorwa kubva patafura ye 'Vashandi':
DELETE * FROM Employees;
Ongorora:Iyo Bvisa chirevo chinobvisa zvinyorwa kubva patafura, asi hachibvise tafura pachayo.I TRUNCATE TABLE
chirevo chinogona zvakare kushandiswa kudzima zvinyorwa kubva patafura, asi kwete iyo tafura pachinzvimbo.
Muenzaniso:
TRUNCATE TABLE table_name;
I DROP
chirevo muSQL chinoshandiswa kudzima tafura kana dhatabhesi.
Iyi inotevera kodhi inodonhedza tafura inonzi 'Vashandi':
DROP TABLE 'Employees';
Ongorora:Tora hanya zvakanyanya paunenge uchishandisa iyo DONHEDZA chirevo. Kana uchidonhedza tafura, ichabvisa zvese zvinyorwa mukati petafura zvakare.Iyi inotevera kodhi inodonhedza dhatabhesi inonzi 'VashandiDB':
DROP DATABASE 'EmployeesDB';
Ongorora:Tora hanya zvakanyanya paunenge uchishandisa iyo DONHEDZA chirevo. Kana uchidonhedza dhatabhesi, ichabvisa matafura ese mukati me database.