So again, the above statement will count only the rows where neither col1 nor col2 is null. Adding up ( SUM) the 1s is equivalent to counting the truths. With only 1s and 0s the * operator works as an equivalent of the logical AND: the final result will be 1 (True) only if each operand is 1 otherwise the result will be 0 (False). In the context of the arithmetic operator * the logical result of the IS NOT NULL operator is implicitly converted to a number, 1 for True, 0 for False. The following shows the syntax of the ROWNUMBER () function: ROWNUMBER () OVER ( PARTITION BY expression1, expression2. cmd.CommandText 'select count (id) from myTable where word '' + word + '' ' cmd.CommandType CommandType.Text int RowCount 0 RowCount Convert.ToInt32 (cmd.ExecuteScalar ()) cmd.CommandText 'select id from myTable where word '' + word + '' ' SQLiteDataReader reader cmd.ExecuteReader () //. Rows are ordered starting from one based on the order specified by the ORDER BY clause in the window definition. SUM( (col1 IS NOT NULL) * (col2 IS NOT NULL) ) The ROWNUMBER () is a window function that assigns a sequential integer to each row of a query’s result set. In particular, you could replace the COUNT with SUM and treat the predicates as numbers (1/0) in an arithmetic expression: SELECT The COUNT() function, which is used for counting the total number of rows in a certain table or query result, is one of the features that make SQLite a. It is possible to shorten the expression somewhat by choosing a less clear syntax. The obvious flaw of this workaround (either variation) is that it is clearly rather unwieldy and will become ridiculously long very quickly as you add more columns to account for. A row will be counted only if neither col1 nor col2 is null. Where instead of the 1 you can put any non-null constant. Or the MySQL-specific IF function: SELECTĬOUNT(IF(col1 IS NOT NULL AND col2 IS NOT NULL, 1, NULL)) It could be either the standard-compliant CASE: SELECTĬOUNT(CASE WHEN col1 IS NOT NULL AND col2 IS NOT NULL THEN 1 END) If that last aspect of the behaviour is what you are trying to achieve, you could emulate it using a conditional inside COUNT. However, one other important point is that a tuple is counted only if none of the individual values in the tuple is null. Obviously, COUNT(DISTINCT) with multiple columns counts unique combinations of the specified columns' values.
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