Runs the query provided and puts the first column of data into an array then frees the result set.
the SQL query or the statement to prepare
which column to return (integer [column number, starting at 0] or string [column name])
array, string or numeric data to be added to the prepared statement. Quantity of items passed must match quantity of placeholders in the prepared statement: meaning 1 placeholder for non-array parameters or 1 placeholder per array element.
If supplied, prepare()/ execute() is used.
array - an ordered array containing data from a result set column or a DB_Error object on failure. The array's index starts at 0.
Table 26-1. Possible PEAR_Error values
Error code | Error message | Reason | Solution |
---|---|---|---|
DB_ERROR_INVALID | invalid | SQL statment for preparing is not valid. | See the prepare() documentation, if you want to use a SQL statemt using placeholders. |
DB_ERROR_MISMATCH | mismatch | Quantity of parameters didn't match quantity of placeholders in the prepared statment. | Check that the number of placeholders in the prepare() statement passed to $query equals the count of entries passed to $params. |
DB_ERROR_NOSUCHFIELD | no such field | Invalid column number/name passed to $col | Use a column number or name that exists in the query result. |
DB_ERROR_NODBSELECTED | no database selected | No database was choosen. | Check the DSN in connect(). |
every other error code | Database specific error | Check the database related section of PHP Manual to detect the reason for this error. In most cases a malformed SQL statement is the cause of the error. (Ie. using LIMIT in a SQL-Statment for an Oracle database.) |
Example 26-1. Using getCol()
Output:
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Example 26-2. Using getCol() to retrieve a numerically specified column
Output:
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Example 26-3. Using getCol() to retrieve a named column
Output:
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Example 26-4. Using getCol() in prepare/execute mode with one placeholder
Output:
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Example 26-5. Using getCol() in prepare/execute mode with two placeholders
Output:
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