Difference between where clause and Having clause with example
| Where clause
|| Having clause
|Where clause can be used with select,update,delete
||Having clause is used for only select query.
|Where clause is applied on each and every row.
||Having clause is applied on group of rows. Continue reading
16) Which command is used to display structure of table?
We can use describe command to display structure of table. We use this command to display columns names,datatypes etc and shows whether column is nullable or not nullable. Continue reading
6) Explain DML statements in SQL?
||Used to retrieve data from database. Continue reading
1) Explain primary key?
Primary key : Primary key is used to uniquely identify a row in table.
Each table can have only one primary key.
We cannot insert nulls for primary key values.
We cannot insert duplicate values in primary key column.
Example : For example if we take Students table students table contains student id, which is used to uniquely identify a record in table. Continue reading