Results for “Relationships & missing data”
Small, practical examples. Search by task or narrow things down below.
Update one row using its primary key
SQL: Use a precise WHERE condition to change only the intended row in a scratch table.
SQL✓ Tested
Update one row using its primary key
SQL Server: Use a precise WHERE condition to change only the intended row in a scratch table.
SQL Server✓ Tested
Update rows selected by a related table
SQL: Use EXISTS to limit updates based on an independent eligibility table.
SQL✓ Tested
Update rows selected by a related table
SQL Server: Use EXISTS to limit updates based on an independent eligibility table.
SQL Server✓ Tested
Update rows selected by a related table
Postgres: Use EXISTS to limit updates based on an independent eligibility table.
Postgres✓ Tested
Update rows selected by a related table
SQLite: Use EXISTS to limit updates based on an independent eligibility table.
SQLite✓ Tested
Update several classifications in one statement
SQL: A CASE expression computes the new value for each row covered by the update predicate.
SQL✓ Tested
Update several classifications in one statement
SQL Server: A CASE expression computes the new value for each row covered by the update predicate.
SQL Server✓ Tested
Update several classifications in one statement
Postgres: A CASE expression computes the new value for each row covered by the update predicate.
Postgres✓ Tested
Update several classifications in one statement
SQLite: A CASE expression computes the new value for each row covered by the update predicate.
SQLite✓ Tested
Use a session-scoped temporary table
Store intermediate rows in a local # table.
temporary table✓ Tested
Use a small table variable
Declare rows for a short batch.
table variable✓ Tested