SQL Table

Table is a collection of data, organized in terms of rows and columns. In DBMS term, table is known as relation and row as tuple.

Note: A table has a specified number of columns, but can have any number of rows.

Table is the simple form of data storage. A table is also considered as a convenient representation of relations.

Let’s see an example of an employee table:

EMP_NAME	ADDRESS	SALARY
Ankit	Lucknow	15000
Raman	Allahabad	18000
Mike	New York	20000

In the above table, “Employee” is the table name, “EMP_NAME”, “ADDRESS” and “SALARY” are the column names. The combination of data of multiple columns forms a row e.g. “Ankit”, “Lucknow” and 15000 are the data of one row.

SQL TABLE Variable

The SQL Table variable is used to create, modify, rename, copy and delete tables. Table variable was introduced by Microsoft.

It was introduced with SQL server 2000 to be an alternative of temporary tables.

It is a variable where we temporary store records and results. This is same like temp table but in the case of temp table we need to explicitly drop it.

Table variables are used to store a set of records. So declaration syntax generally looks like CREATE TABLE syntax.

create table "tablename"  

("column1" "data type",  

"column2" "data type",  

...  

"columnN" "data type"); 

When a transaction rolled back the data associated with table variable is not rolled back.

A table variable generally uses lesser resources than a temporary variable.

Table variable cannot be used as an input or an output parameter.

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Topics of SQL TABLE Statement

SQL TABLE Variable

What TABLE variable can do?SQL CREATE TABLE

How to create a table using SQL query>SQL DROP TABLE

How to drop a table?SQL DELETE TABLE

How to delete all the records of a table?

SQL RENAME TABLE

How to rename a table?SQL TRUNCATE TABLE

How to truncate a table?SQL COPY TABLE

How to copy a table?SQL TEMP TABLE

What is temporary table? What are the advantage of temporary table?SQL ALTER TABLE

How to add, modify, rename and drop column.