Results for “empty”
Small, practical examples. Search by task or narrow things down below.
Increment a counter without an unexpected errexit
Bash Scripts: An assignment avoids the zero-result exit status of a standalone arithmetic post-increment.
Bash Scripts✓ Tested
Increment a stored value in the database
SQL Server: An in-database arithmetic update avoids a separate application read-modify-write step.
SQL Server✓ Tested
Increment a stored value in the database
Postgres: An in-database arithmetic update avoids a separate application read-modify-write step.
Postgres✓ Tested
Insert only keys absent from a destination
SQL Server: NOT EXISTS supports a set-based missing-row insert in a single-writer example.
SQL Server✓ Tested
Insert only keys absent from a destination
Postgres: NOT EXISTS supports a set-based missing-row insert in a single-writer example.
Postgres✓ Tested
Insert or update on a key conflict
Use a unique key to update an existing row.
ON CONFLICT✓ Tested
Inspect deleted rows
Return values from the rows a DELETE removes.
DELETE✓ Tested
Inspect every command status in a pipeline
Bash Scripts: Copy PIPESTATUS immediately before another command overwrites it.
Bash Scripts✓ Tested
Isolate variable changes in a subshell
Bash Scripts: Parentheses create a subshell whose variable assignments do not change the parent.
Bash Scripts✓ Tested
Join a parent to pre-aggregated totals
SQL Server: Aggregate the child rows first to produce at most one joined row per parent.
SQL Server✓ Tested
Join a parent to pre-aggregated totals
Postgres: Aggregate the child rows first to produce at most one joined row per parent.
Postgres✓ Tested
Join array items with a one-character separator
Bash Scripts: A local IFS controls the separator used by the quoted star expansion.
Bash Scripts✓ Tested