Warning, /sdk/codevis/thirdparty/soci/docs/backends/mysql.md is written in an unsupported language. File is not indexed.
0001 # MySQL Backend Reference
0002
0003 SOCI backend for accessing MySQL database.
0004
0005 ## Prerequisites
0006
0007 ### Supported Versions
0008
0009 The SOCI MySQL backend should in principle work with every version of MySQL 5.x.
0010 Some of the features (transactions, stored functions) are not available when MySQL server doesn't support them.
0011
0012 ### Tested Platforms
0013
0014 |MySQL|OS|Compiler|
0015 |--- |--- |--- |
0016 |8.0.1|Windows 10|Visual Studio 2017 (15.3.3)|
0017 |5.5.28|OS X 10.8.2|Apple LLVM version 4.2 (clang-425.0.24)|
0018 |5.0.96|Ubuntu 8.04.4 LTS (Hardy Heron)|g++ (GCC) 4.2.4 (Ubuntu 4.2.4-1ubuntu4)|
0019 |5.7.22|macOS High Sierra 10.13.5|AppleClang 9.1.0.9020039|
0020
0021 ### Required Client Libraries
0022
0023 The SOCI MySQL backend requires MySQL's `libmysqlclient` client library from the [MySQL Connector/C](https://dev.mysql.com/downloads/connector/c/).
0024
0025 Note that the SOCI library itself depends also on `libdl`, so the minimum set of libraries needed to compile a basic client program is:
0026
0027 -lsoci_core -lsoci_mysql -ldl -lmysqlclient
0028
0029 ## Connecting to the Database
0030
0031 To establish a connection to a MySQL server, create a `session` object using the `mysql` backend factory together with a connection string:
0032
0033 session sql(mysql, "db=test user=root password='Ala ma kota'");
0034
0035 // or:
0036 session sql("mysql", "db=test user=root password='Ala ma kota'");
0037
0038 // or:
0039 session sql("mysql://db=test user=root password='Ala ma kota'");
0040
0041 The set of parameters used in the connection string for MySQL is:
0042
0043 * `dbname` or `db` or `service` (required)
0044 * `user`
0045 * `password` or `pass`
0046 * `host`
0047 * `port`
0048 * `unix_socket`
0049 * `sslca`
0050 * `sslcert`
0051 * `local_infile` - should be `0` or `1`, `1` means `MYSQL_OPT_LOCAL_INFILE` will be set.
0052 * `charset`
0053 * `reconnect` - if set to 1, set `MYSQL_OPT_RECONNECT` to reconnect on connection loss.
0054 * `connect_timeout` - should be positive integer value that means seconds corresponding to `MYSQL_OPT_CONNECT_TIMEOUT`.
0055 * `read_timeout` - should be positive integer value that means seconds corresponding to `MYSQL_OPT_READ_TIMEOUT`.
0056 * `write_timeout` - should be positive integer value that means seconds corresponding to `MYSQL_OPT_WRITE_TIMEOUT`.
0057
0058 Once you have created a `session` object as shown above, you can use it to access the database, for example:
0059
0060 int count;
0061 sql << "select count(*) from invoices", into(count);
0062
0063 (See the [connection](../connections.md) and [data binding](../binding.md) documentation
0064 for general information on using the `session` class.)
0065
0066 ## SOCI Feature Support
0067
0068 ### Dynamic Binding
0069
0070 The MySQL backend supports the use of the SOCI `row` class, which facilitates retrieval of data which type is not known at compile time.
0071
0072 When calling `row::get<T>()`, the type you should pass as `T` depends upon the underlying database type.
0073 For the MySQL backend, this type mapping is:
0074
0075 |MySQL Data Type|SOCI Data Type|`row::get<T>` specializations|
0076 |--- |--- |--- |
0077 |FLOAT, DOUBLE, DECIMAL and synonyms|dt_double|double|
0078 |TINYINT, TINYINT UNSIGNED, SMALLINT, SMALLINT UNSIGNED, INT|dt_integer|int|
0079 |INT UNSIGNED|dt_long_long|long long or unsigned|
0080 |BIGINT|dt_long_long|long long|
0081 |BIGINT UNSIGNED|dt_unsigned_long_long|unsigned long long|
0082 |CHAR, VARCHAR, BINARY, VARBINARY, TINYBLOB, MEDIUMBLOB, BLOB,LONGBLOB, TINYTEXT, MEDIUMTEXT, TEXT, LONGTEXT, ENUM|dt_string|std::string|
0083 |TIMESTAMP (works only with MySQL >= 5.0), DATE, TIME, DATETIME|dt_date|std::tm|
0084
0085 (See the [dynamic resultset binding](../types.md#dynamic-binding) documentation for general information
0086 on using the `Row` class.)
0087
0088 ### Binding by Name
0089
0090 In addition to [binding by position](../binding.md#binding-by-position), the MySQL backend supports
0091 [binding by name](../binding.md#binding-by-name), via an overload of the `use()` function:
0092
0093 int id = 7;
0094 sql << "select name from person where id = :id", use(id, "id")
0095
0096 It should be noted that parameter binding of any kind is supported only by means of emulation, since the underlying API used by the backend doesn't provide this feature.
0097
0098 ### Bulk Operations
0099
0100 ### Transactions
0101
0102 [Transactions](../transactions.md) are also supported by the MySQL backend. Please note, however, that transactions can only be used when the MySQL server supports them (it depends on options used during the compilation of the server; typically, but not always, servers >=4.0 support transactions and earlier versions do not) and only with appropriate table types.
0103
0104 ### BLOB Data Type
0105
0106 SOCI `blob` interface is not supported by the MySQL backend.
0107
0108 Note that this does not mean you cannot use MySQL's `BLOB` types. They can be selected using the usual SQL syntax and read into `std::string` on the C++ side, so no special interface is required.
0109
0110 ### RowID Data Type
0111
0112 The `rowid` functionality is not supported by the MySQL backend.
0113
0114 ### Nested Statements
0115
0116 Nested statements are not supported by the MySQL backend.
0117
0118 ### Stored Procedures
0119
0120 MySQL version 5.0 and later supports two kinds of stored routines: stored procedures and stored functions (for details, please consult the [Defining Stored Programs](https://dev.mysql.com/doc/refman/5.5/en/stored-programs-defining.html)). Stored functions can be executed by using SOCI's [procedure class](../procedures.md). There is currently no support for stored procedures.
0121
0122 ## Native API Access
0123
0124 SOCI provides access to underlying datbabase APIs via several `get_backend()` functions, as described in the [Beyond SOCI](../beyond.md) documentation.
0125
0126 The MySQL backend provides the following concrete classes for native API access:
0127
0128 |Accessor Function|Concrete Class|
0129 |--- |--- |
0130 |session_backend * session::get_backend()|mysql_session_backend|
0131 |statement_backend * statement::get_backend()|mysql_statement_backend|
0132
0133 ## Backend-specific extensions
0134
0135 None.
0136
0137 ## Configuration options
0138
0139 None.