Sometimes you need to update a table from the rows in a CSV file. MS SQL offers BULK INSERT FROM and MERGE as a way to achieve this.

BULK INSERT
	mySourceTable
FROM
	'/path/to/data.csv'
WITH (
	FIELDTERMINATOR = ','
	,ROWTERMINATOR = '\n'
	,FIRSTROW = 2
);


MERGE
	myTargetTable AS TargetTable
USING
	mySourceTable AS SourceTable
ON (
	TargetTable.keyField = SourceTable.keyField
)

WHEN MATCHED THEN
	UPDATE SET
		TargetTable.column1 = SourceTable.column1,
		TargetTable.column2 = SourceTable.column2

WHEN NOT MATCHED BY TARGET THEN
	INSERT (
		column1, column2
	) VALUES (
		SourceTable.column1, SourceTable.column2
	);

• Bulk Import (Insert and Update) using BULK INSERT and MERGE Statements in SQL Server 2008
• Using the MERGE Statement to Perform an UPSERT
• MERGE (Transact-SQL)
• Inserting, Updating, and Deleting Data by Using MERGE