The DELETE FROM statement in SQL is used to remove records from a table. Note: The DELETE FROM command cannot delete any rows of data that would violet FOREIGN KEY or other Constraints. Syntax: DELETE FROM “table_name” WHERE “condition”; The WHERE clause is very important here. Without specifying a condition, all records from the table …
In SQL, the DISTINCT keyword is used in SELECT statement to retrieve unique values from a database table. Any duplicate value will show up only once. Syntax: SELECT DISTINCT “column_name” FROM “table_name”; In the above syntax “table_name” is the name of the table where data is stored, and “column_name” is the name of the column …
The SELECT statement in SQL is used to retrieve data from a relational database. Syntax for to select one column: SELECT “column_name” FROM “table_name”; Syntax for to select more than one column: SELECT “column_name1″[,”column_name2”] FROM “table_name”; Syntax for to select ALL : SELECT * FROM “table_name”; In the above all 3 syntax “table_name” is the …
The UPDATE statement is used to modify/update data in a database table. SYNTAX: UPDATE statement is used to modify one column or multiple columns at a time. The syntax for updating one column is : UPDATE “table_name” SET “column_1” = [new value] WHERE “condition”; The syntax for updating multiple columns is: UPDATE “table_name” SET “column_1 …
Usage of UPDATE statement in POSTGRESQL Database Read More »