1 FLAG_FIELD_LENGTH Do not Optimize Column Width The client cannot handle that Connector/ODBC returns the real width of a column. This option was removed in 3.51.18.
2 FLAG_FOUND_ROWS Return Matching Rows The client cannot handle that MySQL returns the true value of affected rows. If this flag is set, MySQL returns “found rows” instead. You must have MySQL 3.21.14 or newer to get this to work.
4 FLAG_DEBUG Trace Driver Calls To myodbc.log Make a debug log in C:\myodbc.log on Windows, or /tmp/myodbc.log on Unix variants. This option was removed in Connector/ODBC 3.51.18.
8 FLAG_BIG_PACKETS Allow Big Results Do not set any packet limit for results and bind parameters. Without this option, parameter binding will be truncated to 255 characters.
16 FLAG_NO_PROMPT Do not Prompt Upon Connect Do not prompt for questions even if driver would like to prompt.
32 FLAG_DYNAMIC_CURSOR Enable Dynamic Cursor Enable or disable the dynamic cursor support.
64 FLAG_NO_SCHEMA Ignore # in Table Name Ignore use of database name in db_name.tbl_name.col_name.
128 FLAG_NO_DEFAULT_CURSOR User Manager Cursors Force use of ODBC manager cursors (experimental).
256 FLAG_NO_LOCALE Do not Use Set Locale Disable the use of extended fetch (experimental).
512 FLAG_PAD_SPACE Pad Char To Full Length Pad CHAR columns to full column length.
1024 FLAG_FULL_COLUMN_NAMES Return Table Names for SQLDescribeCol SQLDescribeCol() returns fully qualified column names.
2048 FLAG_COMPRESSED_PROTO Use Compressed Protocol Use the compressed client/server protocol.
4096 FLAG_IGNORE_SPACE Ignore Space After Function Names Tell server to ignore space after function name and before “(” (needed by PowerBuilder). This makes all function names keywords.
8192 FLAG_NAMED_PIPE Force Use of Named Pipes Connect with named pipes to a mysqld server running on NT.

16384 FLAG_NO_BIGINT Change BIGINT Columns to Int Change BIGINT columns to INT columns (some applications cannot handle BIGINT).

32768 FLAG_NO_CATALOG No Catalog Forces results from the catalog functions, such as SQLTables, to always return NULL and the driver to report that catalogs are not supported.
65536 FLAG_USE_MYCNF Read Options From my.cnf Read parameters from the [client] and [odbc] groups from my.cnf.
131072 FLAG_SAFE Safe Add some extra safety checks.
262144 FLAG_NO_TRANSACTIONS Disable transactions Disable transactions.
524288 FLAG_LOG_QUERY Save queries to myodbc.sql Enable query logging to c:\myodbc.sql(/tmp/myodbc.sql) file. (Enabled only in debug mode.)
1048576 FLAG_NO_CACHE Do not Cache Result (forward only cursors) Do not cache the results locally in the driver, instead read from server (mysql_use_result()). This works only for forward-only cursors. This option is very important in dealing with large tables when you do not want the driver to cache the entire result set.
2097152 FLAG_FORWARD_CURSOR Force Use Of Forward Only Cursors Force the use of Forward-only cursor type. In case of applications setting the default static/dynamic cursor type, and one wants the driver to use noncache result sets, then this option ensures the forward-only cursor behavior.
4194304 FLAG_AUTO_RECONNECT Enable auto-reconnect. Enables auto-reconnection functionality. You should not use this option with transactions, since a auto reconnection during a incomplete transaction may cause corruption. Note that an auto-reconnected connection will not inherit the same settings and environment as the original. This option was added in Connector/ODBC 3.51.13.
8388608 FLAG_AUTO_IS_NULL Flag Auto Is Null When FLAG_AUTO_IS_NULL is set, the driver does not change the default value of sql_auto_is_null, leaving it at 1, so you get the MySQL default, not the SQL standard behavior.
When FLAG_AUTO_IS_NULL is not set, the driver changes the default value of SQL_AUTO_IS_NULL to 0 after connecting, so you get the SQL standard, not the MySQL default behaviour.
Thus, omitting the flag disables the compatibility option and forces SQL standard behaviour.
See IS NULL. This option was added in Connector/ODBC 3.51.13.
16777216 FLAG_ZERO_DATE_TO_MIN Flag Zero Date to Min Translates zero dates (XXXX-00-00) into the minimum date values supported by ODBC, XXXX-01-01. This resolves an issue where some statements will not work because the date returned and the minimum ODBC date value are incompatible. This option was added in Connector/ODBC 3.51.17.
33554432 FLAG_MIN_DATE_TO_ZERO Flag Min Date to Zero Translates the minimum ODBC date value (XXXX-01-01) to the zero date format supported by MySQL (XXXX-00-00). This resolves an issue where some statements will not work because the date returned and the minimum ODBC date value are incompatible. This option was added in Connector/ODBC 3.51.17.
67108864 FLAG_MULTI_STATEMENTS Allow multiple statements Enables support for batched statements. This option was added in Connector/ODBC 3.51.18.
134217728 FLAG_COLUMN_SIZE_S32 Limit column size to 32-bit value Limits the column size to a signed 32-bit value to prevent problems with larger column sizes in applications that do not support them. This option is automatically enabled when working with ADO applications. This option was added in Connector/ODBC 3.51.22.
268435456 FLAG_NO_BINARY_RESULT Always handle binary function results as character data When set this option disables charset 63 for columns with an empty org_table. This option was added in Connector/ODBC 3.51.26.