From 0b307ab3d0c48074b367f573d239e9db8b76a2ca Mon Sep 17 00:00:00 2001 From: Timo Sirainen Date: Fri, 6 Oct 2017 15:52:36 +0300 Subject: [PATCH] lib-sql: Add comments about NULL values. --- src/lib-sql/sql-api.h | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/src/lib-sql/sql-api.h b/src/lib-sql/sql-api.h index b0ac3c1b99..6911900b0c 100644 --- a/src/lib-sql/sql-api.h +++ b/src/lib-sql/sql-api.h @@ -179,15 +179,22 @@ const char *sql_result_get_field_name(struct sql_result *result, /* Return field index for given name, or -1 if not found. */ int sql_result_find_field(struct sql_result *result, const char *field_name); -/* Returns value of given field as string. */ +/* Returns value of given field as string. Note that it can be NULL. */ const char *sql_result_get_field_value(struct sql_result *result, unsigned int idx); +/* Returns a binary value. Note that a NULL is returned as NULL with size=0, + while empty string returns non-NULL with size=0. */ const unsigned char * sql_result_get_field_value_binary(struct sql_result *result, unsigned int idx, size_t *size_r); +/* Find the field and return its value. NULL return value can mean that either + the field didn't exist or that its value is NULL. */ const char *sql_result_find_field_value(struct sql_result *result, const char *field_name); -/* Return all values of current row. */ +/* Return all values of current row. Note that this array is not + NULL-terminated - you must use sql_result_get_fields_count() to find out + the array's length. It's also possible that some of the values inside the + array are NULL. */ const char *const *sql_result_get_values(struct sql_result *result); /* Return last error message in result. */ -- 2.47.3