Results for “empty”
Small, practical examples. Search by task or narrow things down below.
Keep rows matching a condition
SQL Server: Use WHERE to select rows with a particular category.
SQL Server✓ Tested
Keep rows matching a condition
Postgres: Use WHERE to select rows with a particular category.
Postgres✓ Tested
Keep spaces inside one argument
Linux Commands: Keep spaces inside one argument using GNU/Linux commands in an empty practice directory.
Linux Commands✓ Tested
Limit a beginner function variable to local scope
Bash Scripts: Limit a beginner function variable to local scope with a small standalone Bash program.
Bash Scripts✓ Tested
List unordered pairs without duplicate reversals
SQL Server: Join using an increasing key comparison to omit self-pairs and reversed duplicates.
SQL Server✓ Tested
List unordered pairs without duplicate reversals
Postgres: Join using an increasing key comparison to omit self-pairs and reversed duplicates.
Postgres✓ Tested
Load functions from a trusted local script
Bash Scripts: Source executes a file in the current shell so its function definitions remain available.
Bash Scripts✓ Tested
Look up values in an associative array
Use named keys for a small in-memory configuration table.
dictionary✓ Tested
Loop over an array safely
Preserve spaces in array elements while iterating.
array✓ Tested
Make a Compose service’s filesystem read-only
Docker / Compose: Make a Compose service’s filesystem read-only in a small Compose file.
Docker / Compose✓ Tested
Make a pair of columns unique together
SQL Server: A composite primary key permits repeated individual values while forbidding a duplicate combination.
SQL Server✓ Tested
Make a pair of columns unique together
Postgres: A composite primary key permits repeated individual values while forbidding a duplicate combination.
Postgres✓ Tested