Update if a key, or combination of keys, exists, otherwise INSERT
26327
Solutions for INSERT OR UPDATE on SQL Server
136992
"Insert if not exists" statement in SQLite
156640
How can I check if a string exists in another string
61724
MySQL - UPDATE multiple rows with different values in one query
135734
How to add column if not exists on PostgreSQL?
106065
How to check if a Constraint exists in Sql server?
158985
Can a foreign key be NULL and/or duplicate?
18575
How to 'insert if not exists' in MySQL?
102293
INSERT INTO if not exists SQL server
128373
How do I delete unique rows from a table with duplicate keys?
112077
How to check if a value already exists to avoid duplicates?
117531
Best practice between using LEFT JOIN or NOT EXISTS
99497
IF EXISTS taking longer than embedded select statement
62976
Concatenating a string and primary key Id while inserting
63056
Subquery using Exists 1 or Exists *
124353
Updating a DE with no Primary Keys
116239
Does SQL Server Offer Anything Like MySQL's ON DUPLICATE KEY UPDATE