Results for “IS NULL”
Small, practical examples. Search by task or narrow things down below.
Count the rows in a table
SQL: COUNT(*) includes every row, including rows with NULL columns.
SQL✓ Tested
Count the rows in a table
SQL Server: COUNT(*) includes every row, including rows with NULL columns.
SQL Server✓ Tested
Count the rows in a table
Postgres: COUNT(*) includes every row, including rows with NULL columns.
Postgres✓ Tested
Count the rows in a table
SQLite: COUNT(*) includes every row, including rows with NULL columns.
SQLite✓ Tested
Detect truncated formatted output
Arduino / C: snprintf returns the length it would have written, excluding the null terminator.
Arduino / C✓ Tested
Find the first occurrence of a character
C: strchr returns a pointer into the input or NULL if the character is absent.
C✓ Tested
Format several integers in a fixed buffer
Arduino / C: snprintf limits writes to the buffer size and includes a terminating null byte.
Arduino / C✓ Tested
Join values with a delimiter
Concatenate rows in a specified order.
group_concat✓ Tested
Read a nested value safely
Combine optional chaining with nullish coalescing in JavaScript.
JavaScript✓ Tested
Read serial text up to a delimiter
Arduino / C: readBytesUntil excludes the delimiter and does not add a null terminator.
Arduino / C✓ Tested
Reject a negative quantity with CHECK
SQL: Combine NOT NULL and CHECK because an unknown NULL check result is normally accepted.
SQL✓ Tested
Reject a negative quantity with CHECK
SQL Server: Combine NOT NULL and CHECK because an unknown NULL check result is normally accepted.
SQL Server✓ Tested