HJ

Leave HJ’s trace, All-In

[SQL First Step] 20. Getting the Number of Rows - COUNT

Aggregate function and COUNT

[SQL First Step] 19. Hard Delete and Soft Delete

Hard delete and Soft delete

[SQL First Step] 18. Data Updating - UPDATE

UPDATE

[SQL First Step] 17. Deleting - DELETE

Delete rows with DELETE

[SQL First Step] 16. Adding Row - INSERT

INSERT