The snippet library.
Small, practical examples. Search by task or narrow things down below.
Match a known text prefix
Postgres: A percent wildcard matches zero or more characters following the prefix.
Postgres✓ Tested
Match a text prefix
Postgres: Use a percent wildcard after a known prefix.
Postgres✓ Tested
Match one value from a short list
Postgres: Use IN for a set of allowed values.
Postgres✓ Tested
Measure the length of ordinary text
Postgres: Use the engine’s text-length function; this ASCII example has no trailing spaces.
Postgres✓ Tested
Normalize ASCII text to lowercase
Postgres: LOWER is useful for display normalization; indexed case-insensitive search depends on the database collation and schema.
Postgres✓ Tested
Normalize ASCII text to uppercase
Postgres: UPPER changes character case under the database’s text rules.
Postgres✓ Tested
Number rows within each group
Assign ordered row numbers with a window function.
row_number✓ Tested
Pair employees with their managers
Postgres: Alias a table twice to represent two different roles in one relationship.
Postgres✓ Tested
Place missing values after known values portably
Postgres: A CASE sort key controls NULL placement without relying on engine-specific defaults.
Postgres✓ Tested
Rank tied scores with competition gaps
Postgres: RANK leaves a gap after tied rows, unlike DENSE_RANK.
Postgres✓ Tested
Rank tied scores without gaps
Postgres: DENSE_RANK assigns equal ranks to ties and increments by one for the next distinct score.
Postgres✓ Tested
Read a JSONB field as text
Extract a nested value from a JSON document.
jsonb✓ Tested