PostgreSQL – COUNT Function

ByAdmin

The count() function in PostgreSQL is used to count the number of rows in a table or the number of values in a specific column that meet a certain condition.

Below is the basic syntax of the count() function:

SELECT count(*)
FROM table_name;

Above query will count the total number of rows in the specified table. You can also specify a specific column to count the number of non-null values in that column:

SELECT count(column_name)
FROM table_name;

If you want to count the number of rows that meet a certain condition, you can add a WHERE clause to the query:

SELECT count(*)
FROM table_name
WHERE column_name = 'value';

You can also count the number of distinct values in a column by using the DISTINCT keyword. This will count the number of unique values in the specified column.

SELECT count(DISTINCT column_name)
FROM table_name;

To count the number of rows that meet multiple conditions, you can use the AND or OR operators in the WHERE clause.

SELECT count(*) FROM table_name WHERE column1 = 'value1' AND column2 = 'value2';

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