Can we use case in where clause in SQL Server?
CASE STATEMENT IN WHERE CLAUSE:
We can use a case statement in Where, Order by and Group by clause. … So, by using a CASE statement with the where condition displays the result.
Is case important in SQL?
The SQL Keywords are case-insensitive ( SELECT , FROM , WHERE , etc), but are often written in all caps. However in some setups table and column names are case-sensitive.
Can we use case in select statement?
CASE can be used in any statement or clause that allows a valid expression. For example, you can use CASE in statements such as SELECT, UPDATE, DELETE and SET, and in clauses such as select_list, IN, WHERE, ORDER BY, and HAVING.
Can we put case in where clause?
You can use a CASE Statement anywhere a valid expression is used within the SELECT statement such as the WHERE clause’s filter criteria.
How do you do not in SQL?
Overview. The SQL Server NOT IN operator is used to replace a group of arguments using the <> (or !=) operator that are combined with an AND. It can make code easier to read and understand for SELECT, UPDATE or DELETE SQL commands.
What are all DDL commands?
Data Definition Language (DDL) commands:
- CREATE to create a new table or database.
- ALTER for alteration.
- Truncate to delete data from the table.
- DROP to drop a table.
- RENAME to rename a table.
How many tables can be join in SQL query?
Theoretically, there is no upper limit on the number of tables that can be joined using a SELECT statement. (One join condition always combines two tables!) However, the Database Engine has an implementation restriction: the maximum number of tables that can be joined in a SELECT statement is 64.
Where is PostgreSQL?
PostgreSQL WHERE clause overview
The WHERE clause uses the condition to filter the rows returned from the SELECT clause. The condition must evaluate to true, false, or unknown. It can be a boolean expression or a combination of boolean expressions using the AND and OR operators.
What is decode in PostgreSQL?
PostgreSQL DECODE() function is used to decode or extract the binary data from the input string, which is in textual format and which has been encoded by using PostgreSQL Encode() function. … The PostgreSQL supports various formats for Encode and DECODE functions such as base64, escape, etc.
How do I write a cast in PostgreSQL?
PostgreSQL provides you with the CAST operator that allows you to do this. In this syntax: First, specify an expression that can be a constant, a table column, an expression that evaluates to a value. Then, specify the target data type to which you want to convert the result of the expression.