Explain Codes LogoExplain Codes Logo

Sql

Find duplicate entries in a column

sql
fuzzy-matching
performance-considerations
analytical-functions

Sort by Minimum Value of Two Columns

sql
best-practices
performance
sql-performance

My Select SUM query returns null. It should return 0

sql
null-values
aggregate-functions
coalesce

What is the simplest SQL Query to find the second largest value?

sql
prompt-engineering
best-practices
join

Maintaining order in MySQL "IN" query

sql
performance
best-practices
indexing

Select * EXCEPT

sql
dynamic-sql
sql-injection
database-security

Adding a new SQL column with a default value

sql
database-management
sql-queries
data-types

Will ANSI JOIN vs. non-ANSI JOIN queries perform differently?

sql
join
best-practices
query-plans

How can I import a SQL file into a Rails database?

sql
database-connection
rails-migration
sql-import

Is there any difference between "!=" and "<>" in Oracle Sql?

sql
best-practices
performance
sql-standards

Add a column to a table with a default value equal to the value of an existing column

sql
database-expert
performance-optimization
data-integrity

Bulk insert, update if on conflict (bulk upsert) on Postgres

sql
bulk-insert
upsert
postgresql

Pl/pgsql checking if a row exists

sql
performance
best-practices
database-optimization

How do I do multiple CASE WHEN conditions using SQL Server 2008?

sql
best-practices
join
case-statement

How to do pagination in SQL Server 2008

sql
pagination
sql-server
performance

How do composite indexes work?

sql
indexing
database-optimization
query-performance

T-sql: Selecting Column Based on MAX(Other Column)

sql
window-functions
join-optimization
sql-performance

How to join on multiple criteria, returning all combinations of both criteria?

sql
join
sqlfiddle
best-practices

How to include BIT type column in SELECT part without including it on the GROUP BY in T-SQL?

sql
aggregate-functions
sql-queries
t-sql

Foreign key constraints: When to use ON UPDATE and ON DELETE

sql
database-design
foreign-keys
data-consistency