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SQL EXISTS subqueries should not be used

Rule description

  • SQL EXISTS subqueries should not be used

 

Non-compliant Code Example

SELECT 
    NAME,
    ADDRESS,
    CREDIT_LIMIT       
FROM
    CUSTOMERS
WHERE EXISTS (SELECT NAME FROM VENDOR WHERE NAME IS NOT NULL) --Non compliant code (SQL EXISTS sub-queries is be used)

Compliant Code Example

SELECT 
    NAME,
    ADDRESS,
    CREDIT_LIMIT       
FROM
    CUSTOMERS
INNER JOIN VENDOR 
	ON VENDOR.NAME IS NOT NULL AND VENDOR.NAME = CUSTOMERS.NAME;  --Compliant code (SQL EXISTS sub-queries is not used)
Visual Expert 2020
 VEPLSQLRULE102