Skip to main content

SELECT, INSERT, DELETE and UPDATE Statements in SQL Server

SELECT 
Select statement use to retrieve data from table, the result is store in result table called Result-Set.
Syntax:
SELECT <column's name> FROM <Table Name>
Example:
IF OBJECT_ID('dbo.Employee', 'U') IS NOT NULL
       DROP TABLE Employee
CREATE TABLE Employee
(
       ID INT IDENTITY(1,1),
       FNAME VARCHAR(50),
       LNAME VARCHAR(50),
       ADDRESS VARCHAR(1000),
       CREATEDDATE DATETIME
)
INSERT INTO Employee (FNAME,LNAME,ADDRESS,CREATEDDATE) VALUES('DILIP','SINGH','DELHI',GETDATE())
INSERT INTO Employee (FNAME,LNAME,ADDRESS,CREATEDDATE) VALUES('VIPUL','BHATT','NOIDA',GETDATE())
INSERT INTO Employee (FNAME,LNAME,ADDRESS,CREATEDDATE) VALUES('RAJ','SINGH','BOKARO',GETDATE())
First run above code, it will create table "Employee" and also will insert  three records in table.
Select Statement
SELECT * FROM Employee
Above query will return all the columns in result-set.
Result







Select statement with column name
SELECT FNAME,LNAME,ADDRESS FROM Employee
It will return column 'FNAME','LNAME','ADDRESS' in result-set.

Result







INSERT
Insert statement use for insert new records into table.
Syntax:
INSERT INTO <table name> VALUES <values>
Example:
IF OBJECT_ID('dbo.Employee', 'U') IS NOT NULL
       DROP TABLE Employee
CREATE TABLE Employee
(
       ID INT IDENTITY(1,1),
       FNAME VARCHAR(50),
       LNAME VARCHAR(50),
       ADDRESS VARCHAR(1000),
       CREATEDDATE DATETIME
)
Run above query then select statement as bellow.
SELECT * FROM Employee
You will find no records
Insert Statements
INSERT INTO Employee (FNAME,LNAME,ADDRESS,CREATEDDATE) VALUES('DILIP','SINGH','DELHI',GETDATE())
INSERT INTO Employee (FNAME,LNAME,ADDRESS,CREATEDDATE) VALUES('VIPUL','BHATT','NOIDA',GETDATE())
INSERT INTO Employee (FNAME,LNAME,ADDRESS,CREATEDDATE) VALUES('RAJ','SINGH','BOKARO',GETDATE())
Again run select statement.
SELECT * FROM Employee
Result







DELETE
Delete statement use to delete records from table.
Syntax:
DELETE FROM <table name> WHERE <condition>
Example:
IF OBJECT_ID('dbo.Employee', 'U') IS NOT NULL
       DROP TABLE Employee
CREATE TABLE Employee
(
       ID INT IDENTITY(1,1),
       FNAME VARCHAR(50),
       LNAME VARCHAR(50),
       ADDRESS VARCHAR(1000),
       CREATEDDATE DATETIME
)
INSERT INTO Employee (FNAME,LNAME,ADDRESS,CREATEDDATE) VALUES('DILIP','SINGH','DELHI',GETDATE())
INSERT INTO Employee (FNAME,LNAME,ADDRESS,CREATEDDATE) VALUES('VIPUL','BHATT','NOIDA',GETDATE())
INSERT INTO Employee (FNAME,LNAME,ADDRESS,CREATEDDATE) VALUES('RAJ','SINGH','BOKARO',GETDATE())
Run above query then select statement

SELECT * FROM Employee
 Result







Delete Statement
DELETE FROM Employee
Note: this query will delete all records of table

Delete records with condition, where clause use for condition
DELETE FROM Employee WHERE FNAME='DILIP'
Now run select statement
SELECT * FROM Employee
Result







Above result set show, the row which FNAME is DILIP has been deleted from table.

UPDATE
Update statement use to update particular column record in table.
Syntax:
UPDATE <table name> SET <column name> WHERE <condition>
Example:
IF OBJECT_ID('dbo.Employee', 'U') IS NOT NULL
       DROP TABLE Employee
CREATE TABLE Employee
(
       ID INT IDENTITY(1,1),
       FNAME VARCHAR(50),
       LNAME VARCHAR(50),
       ADDRESS VARCHAR(1000),
       CREATEDDATE DATETIME
)
INSERT INTO Employee (FNAME,LNAME,ADDRESS,CREATEDDATE)
 VALUES('DILIP','SINGH','DELHI',GETDATE())
INSERT INTO Employee (FNAME,LNAME,ADDRESS,CREATEDDATE) VALUES('VIPUL','BHATT','NOIDA',GETDATE())
INSERT INTO Employee (FNAME,LNAME,ADDRESS,CREATEDDATE) VALUES('RAJ','SINGH','BOKARO',GETDATE())
Run above query then select statement 

Result







Update Statement
UPDATE Employee SET ADDRESS='GORAKHPUR' 
It will update ADDRESS column with 'GORKHPUR' of all table row.
Run select statement
SELECT * FROM Employee
Result







Update Statement with  condition
UPDATE Employee SET ADDRESS='GORAKHPUR' WHERE FNAME='DILIP'
run select statement
SELECT * FROM Employee
Result

Popular posts from this blog

Check for changes to an SQL Server table?

Problem: Suppose your team is working on the under-development project so it might be possible continuous work on the database and perform changes in Table, Stored procedure as per requirement, and daily you have to update the testing server database as per changes are done in developing server database then how it is possible to trace those changes. There are a lot of solutions for this problem which is listed below Solution 1: For SQL Server 2000, 2005 and above use the CHECKSUM command SELECTCHECKSUM_AGG(BINARY_CHECKSUM(*))FROMYour_Table_NameWITH (NOLOCK); That will return the same number each time its run as long as the table contents haven't changed. Unfortunately CHECKSUM does not work always properly to detect changes. It is only a primitive checksum and no CRC calculation. Therefore you can't use it to detect all changes, e. g. symmetrical changes result in the same CHECKSUM! Solution 2: 1.Run the following query. Before executing query replace DB_Name with your database name…

How to drop multiple tables with common prefix in one query?

Problem: Suppose we have a situation where we need to drop those tables that have some prefixes string, so it is possible to drop those tables with a common prefix in a single query.
Solution: yes it is possible to drop all those tables that have the common prefix in a single query. Using following query you can delete all those tables that begin with a certain prefix string. In where condition just put the common prefix string in where condition (Like ‘prefix%’)
DECLARE@queryNVARCHAR(MAX)=N'';
SELECT@query+=' DROP TABLE ' +QUOTENAME(s.name) +'.'+QUOTENAME(t.name)+';' FROMsys.tablesASt INNERJOINsys.schemasASs ONt.[schema_id]=s.[schema_id] WHEREt.nameLIKE'MX_100%';
EXECsp_executesql@query;
This query may create an issue, if a table has a foreign key relationship, you'll either need to drop them first or arrange the output to drop the tables in a certain order. If you want to monitor exactly what goes on when the query is running then use the following que…

Merge and Merge join transformation in SSIS