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21.1.4.3 Configuring a Connector/ODBC DSN on Windows »
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21.1.4.2. Connector/ODBC Connection Parameters

You can specify the parameters in the following tables for Connector/ODBC when configuring a DSN. Users on Windows can use the Options and Advanced panels when configuring a DSN to set these parameters; see the table for information on which options relate to which fields and checkboxes. On Unix and Mac OS X, use the parameter name and value as the keyword/value pair in the DSN configuration. Alternatively, you can set these parameters within the InConnectionString argument in the SQLDriverConnect() call.

Parameter Default Value Comment
user ODBC The user name used to connect to MySQL.
uid ODBC Synonymous with user. Added in 3.51.16.
server localhost The host name of the MySQL server.
database   The default database.
option 0 Options that specify how Connector/ODBC should work. See below.
port 3306 The TCP/IP port to use if server is not localhost.
initstmt   Initial statement. A statement to execute when connecting to MySQL. In version 3.51 the parameter is called stmt. Note, the driver supports the initial statement being executed only at the time of the initial connection.
password   The password for the user account on server.
pwd   Synonymous with password. Added in 3.51.16.
socket   The Unix socket file or Windows named pipe to connect to if server is localhost.
sslca   The path to a file with a list of trust SSL CAs. Added in 3.51.16.
sslcapath   The path to a directory that contains trusted SSL CA certificates in PEM format. Added in 3.51.16.
sslcert   The name of the SSL certificate file to use for establishing a secure connection. Added in 3.51.16.
sslcipher   A list of allowable ciphers to use for SSL encryption. The cipher list has the same format as the openssl ciphers command Added in 3.51.16.
sslkey   The name of the SSL key file to use for establishing a secure connection. Added in 3.51.16.
charset   The character set to use for the connection. Added in 3.51.17.
sslverify   If set to 1, the SSL certificate will be verified when used with the MySQL connection. If not set, then the default behavior is to ignore SSL certificate verification.
readtimeout   The timeout in seconds for attempts to read from the server. Each attempt uses this timeout value and there are retries if necessary, so the total effective timeout value is three times the option value. You can set the value so that a lost connection can be detected earlier than the TCP/IP Close_Wait_Timeout value of 10 minutes. This option works only for TCP/IP connections, and only for Windows prior to MySQL 5.1.12. Corresponds to the MYSQL_OPT_READ_TIMEOUT option of the MySQL Client Library. This option was added in Connector/ODBC 3.51.27.
writetimeout   The timeout in seconds for attempts to write to the server. Each attempt uses this timeout value and there are net_retry_count retries if necessary, so the total effective timeout value is net_retry_count times the option value. This option works only for TCP/IP connections, and only for Windows prior to MySQL 5.1.12. Corresponds to the MYSQL_OPT_WRITE_TIMEOUT option of the MySQL Client Library. This option was added in Connector/ODBC 3.51.27.

Note

The SSL configuration parameters can also be automatically loaded from a my.ini or my.cnf file.

The option argument is used to tell Connector/ODBC that the client isn't 100% ODBC compliant. On Windows, you normally select options by toggling the checkboxes in the connection screen, but you can also select them in the option argument. The following options are listed in the order in which they appear in the Connector/ODBC connect screen.

Value Flagname GUI Option Description
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 behavior.

Thus, omitting the flag disables the compatibility option and forces SQL standard behavior.

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.

To select multiple options, add together their values. For example, setting option to 12 (4+8) gives you debugging without packet limits.

Note

From version of MySQL Connector/ODBC 5.1.6 onwards, it is possible to use the flag name directly as a parameter in the connection string, by using the flag name without the FLAG_ prefix. So, in addition to using the options parameter with various flags set, it is now possible to use the flags directly as parameters. For example, FIELD_LENGTH, FOUND_ROWS and DEBUG could all be used as parameters.

The following table shows some recommended option values for various configurations.

Configuration Option Value
Microsoft Access, Visual Basic 3
Driver trace generation (Debug mode) 4
Microsoft Access (with improved DELETE queries) 35
Large tables with too many rows 2049
Sybase PowerBuilder 135168
Query log generation (Debug mode) 524288
Generate driver trace as well as query log (Debug mode) 524292
Large tables with no-cache results 3145731

User Comments

Posted by Dormakov Nikolay on October 9 2008 10:19am[Delete] [Edit]

Information is absent about where should be situated my.cnf file and what parameters is included to [odbc] part.

"Read parameters from the [client] and [odbc] groups from my.cnf."

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