Tutorial Gateway

  • C
  • C#
  • Python
  • SQL
  • Java
  • JS
  • BI Tools
    • Informatica
    • Talend
    • Tableau
    • Power BI
    • SSIS
    • SSRS
    • SSAS
    • MDX
    • R Tutorial
    • Alteryx
    • QlikView
  • More
    • C Programs
    • C++ Programs
    • Go Programs
    • Python Programs
    • Java Programs
  • MySQL

SQL LEFT Function

The SQL left function returns the leftmost characters from a given expression. The SQL Server left function uses its second argument to decide how many left characters it should return. The syntax of the string Left Function is

SELECT LEFT (Character_Expression, Value)
FROM [Source]
  • Character_Expression: LEFT Function will write the left most characters from this expression.
  • Value: How many characters you want to extract from the Character_Expression.

The index position in Sql Server LEFT Function will start from 1, Not 0. For this SQL Server LEFT Function example, we use the below-shown data

SQL LEFT FUNCTION

SQL LEFT Function Example 1

The LEFT function returns the specified number of leftmost characters from the given string. The following LEFT function query returns left most 3 and 20 characters.

DECLARE @Charcater_Expression varchar(50)
SET @Charcater_Expression = 'Learn SQL Server' 

--Using Positive Integer 3 -- SQL
SELECT LEFT (@Charcater_Expression, 5) AS 'SQL LEFT' 

--Searching from specific position – 20
SELECT LEFT (@Charcater_Expression, 20) AS 'SQL LEFT' 
SQL LEFT FUNCTION 1

We used the left function to return five leftmost characters from the @Character_Expression variable.

--Using Positive Integer -- SQL
SELECT LEFT (@Charcater_Expression, 5) AS 'SQL LEFT'

In the next line, We assigned 20 to the second argument, which is greater than the string length. So, the LEFT function will return all the characters from the @Character_Expression

--Searching from specific position – 20
SELECT LEFT (@Charcater_Expression, 20) AS 'SQL LEFT'

LEFT Function Example 2

The SQL Server Left function also allows you to select the leftmost characters from the column values. In this SQL Server example, we will return the left four words of all the records present inside the Department Name column

-- Sql Server Left Function Example
SELECT [FirstName]
      ,[LastName]
      ,[DepartmentName]
      ,LEFT ([DepartmentName], 4) AS [SQL LEFT]
 FROM [Employe]
SQL LEFT FUNCTION 2

NOTE: If you observe the second record, there is an Empty space after the Sr.

Character before @ using LEFT Function Example 3

Let us find the index position of a @ symbol present in the Email column using the CHARINDEX function. Next, this String Function will extract the left-most characters up to @ symbol using the string left Function

-- Left function in Sql Server
SELECT [FirstName]
      ,[LastName]
      ,[DepartmentName]
      ,[Email]
      ,LEFT (
              [Email]
      ,CHARINDEX ('@', [Email]) - 1
            ) AS [SQL LEFT]
 FROM [Employe]
SQL LEFT FUNCTION 3

The below statement returns the index position of the @ symbol. It suggests the CHARINDEX function finds the index position of @ symbol in every record.

CHARINDEX ('@', [Email])

We reduced the index position by 1, using the below statement. If you miss this, sql left output include @ symbol as well

CHARINDEX ('@', [Email]) - 1

Filed Under: SQL

  • Install SQL Server
  • Install SQL Management Studio
  • Uninstall Management Studio
  • Install AdventureWorks Database
  • SQL Management Studio Intro
  • Connect SQL with sqlcmd utility
  • SQL Attach Database
  • SQL Detach Database
  • SQL Restore Database
  • Restore Database using BAK
  • SQL Rename Database with Files
  • Get SQL Database Names
  • SQL Create Table
  • SQL Rename Table
  • SQL Alter Table
  • SQL Add Column
  • SQL Rename Column
  • Get SQL Table Names in a DB
  • Find SQL Table Dependencies
  • Rename SQL Table & Column
  • SQL Global & Local Temp Table
  • SQL Table Variable
  • SQL Derived Table
  • SQL DATALENGTH
  • SQL Data Types
  • DML, DDL, DCL & TCL Cmds
  • SQL Query Builder
  • SQL ALIAS
  • SQL SELECT Statement
  • SQL SELECT DISTINCT
  • SQL SELECT INTO Statement
  • SQL INSERT Statement
  • SQL INSERT INTO SELECT
  • SQL BULK INSERT or BCP
  • SQL UPDATE Statement
  • SQL UPDATE from SELECT
  • SQL DELETE Statement
  • SQL TRUNCATE Table
  • SQL CASE Statement
  • SQL MERGE Statement
  • SQL Subquery
  • SQL CTE
  • SQL PIVOT
  • SQL UNPIVOT
  • SQL Clauses Examples
  • SQL TOP Clause
  • SQL WHERE Clause
  • SQL ORDER BY Clause
  • SQL GROUP BY Clause
  • SQL HAVING Clause
  • SQL Primary Key
  • SQL Foreign Key
  • SQL Referential Integrity
  • SQL Check Constraint
  • SQL Unique Constraint
  • SQL Default Constraint
  • SQL Clustered Index
  • SQL Non Clustered Index
  • SQL Filtered Indexes
  • SQL COALESCE Function
  • SQL IS NOT NULL
  • SQL IS NULL Function
  • SQL ISNULL
  • SQL JOINS
  • SQL CROSS JOIN
  • SQL FULL JOIN
  • SQL SELF JOIN
  • SQL Outer Joins
  • SQL Cross Join Vs Inner Join
  • SQL LEFT JOIN
  • SQL RIGHT JOIN
  • SQL AND & OR Operators
  • SQL Arithmetic Operators
  • SQL BETWEEN Operator
  • SQL Comparison Operators
  • SQL LIKE
  • SQL EXCEPT
  • SQL EXISTS Operator
  • SQL NOT EXISTS Operator
  • SQL INTERSECT
  • SQL IN Operator
  • SQL NOT IN Operator
  • SQL UNION
  • SQL UNION ALL
  • SQL IF ELSE
  • SQL ELSE IF
  • SQL WHILE LOOP
  • SQL Nested While Loop
  • SQL BREAK Statement
  • SQL CONTINUE Statement
  • SQL GOTO Statement
  • SQL IIF Function
  • SQL CHOOSE Function
  • SQL Change Data Capture
  • SQL Table Partitioning
  • SQL Table Partition using SSMS
  • SQL TRY CATCH
  • SQL VIEWS
  • SQL User Defined Functions
  • SQL Alter User Defined Functions
  • SQL Stored Procedure Intro
  • Useful System Stored Procedures
  • SQL SELECT Stored Procedure
  • SQL INSERT Stored Procedure
  • SQL UPDATE Stored Procedure
  • Stored Procedure Return Values
  • Stored Procedure Output Params
  • Stored Procedure Input Params
  • Insert SP result into Temp Table
  • SQL Triggers Introduction
  • SQL AFTER INSERT Triggers
  • SQL AFTER UPDATE Triggers
  • SQL AFTER DELETE Triggers
  • SQL INSTEAD OF INSERT
  • SQL INSTEAD OF UPDATE
  • SQL INSTEAD OF DELETE
  • SQL STATIC CURSOR
  • SQL DYNAMIC CURSOR
  • SQL FORWARD_ONLY Cursor
  • SQL FAST_FORWARD CURSOR
  • SQL KEYSET CURSOR
  • SQL TRANSACTIONS
  • SQL Nested Transactions
  • SQL ACID Properties
  • Create SQL Windows Login
  • Create SQL Server Login
  • SQL Server Login Error
  • Create SQL Server Roles
  • SQL Maintenance Plan
  • Backup SQL Database
  • SQL Ranking Functions Intro
  • SQL RANK Function
  • SQL PERCENT_RANK Function
  • SQL DENSE_RANK Function
  • SQL NTILE Function
  • SQL ROW_NUMBER
  • SQL Aggregate Functions
  • SQL Date Functions
  • SQL Mathematical Functions
  • SQL String Functions
  • SQL CAST Function
  • SQL TRY CAST
  • SQL CONVERT
  • SQL TRY CONVERT
  • SQL PARSE Function
  • SQL TRY_PARSE Function
  • SQL Calculate Running Total
  • SQL Find Nth Highest Salary
  • SQL Reverse String
  • SQL FOR XML PATH
  • SQL FOR XML AUTO
  • SQL FOR XML RAW

Copyright © 2021· All Rights Reserved by Suresh.
About | Contact | Privacy Policy