Setting The Result Of An SQL Function

The sqlite3_result_text(), sqlite3_result_text16(), sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces set the return value of the application-defined function to be a text string which is represented as UTF-8, UTF-16 native byte order, UTF-16 little endian, or UTF-16 big endian, respectively.

The sqlite3_result_text64() interface sets the return value of an application-defined function to be a text string in an encoding specified by the fifth (and last) parameter, which must be one of SQLITE_UTF8, SQLITE_UTF16, SQLITE_UTF16BE, or SQLITE_UTF16LE.

SQLite takes the text result from the application from the 2^nd parameter of the sqlite3_result_text* interfaces.

If the 3^rd parameter to the sqlite3_result_text* interfaces is negative, then SQLite takes result text from the 2^nd parameter through the first zero character.

If the 3^rd parameter to the sqlite3_result_text* interfaces is non-negative, then as many bytes (not characters) of the text pointed to by the 2^nd parameter are taken as the application-defined function result.

If the 3^rd parameter is non-negative, then it must be the byte offset into the string where the NUL terminator would appear if the string where NUL terminated. If any NUL characters occur in the string at a byte offset that is less than the value of the 3^rd parameter, then the resulting string will contain embedded NULs and the result of expressions operating on strings with embedded NULs is undefined.

If the 4^th parameter to the sqlite3_result_text* interfaces or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that function as the destructor on the text or BLOB result when it has finished using that result.

If the 4^th parameter to the sqlite3_result_text* interfaces or to sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite assumes that the text or BLOB result is in constant space and does not copy the content of the parameter nor call a destructor on the content when it has finished using that result.

If the 4^th parameter to the sqlite3_result_text* interfaces or sqlite3_result_blob is the special constant SQLITE_TRANSIENT then SQLite makes a copy of the result into space obtained from sqlite3_malloc() before it returns.