To perform XA transactions in MySQL, use the following statements:要在MySQL中执行XA事务，请使用以下语句：
XA {START|BEGIN} xid [JOIN|RESUME]
XA END xid [SUSPEND [FOR MIGRATE]]
XA PREPARE xid
XA COMMIT xid [ONE PHASE]
XA ROLLBACK xid
XA RECOVER [CONVERT XID]
For 对于XA START, the JOIN and RESUME clauses are recognized but have no effect.XA START，可以识别JOIN和RESUME子句，但不起作用。
For 对于XA END the SUSPEND [FOR MIGRATE] clause is recognized but has no effect.XA END，可以识别SUSPEND [For MIGRATE]子句，但不起作用。
Each XA statement begins with the 每个XA语句都以XA keyword, and most of them require an xid value. XA关键字开头，其中大多数语句都需要xid值。An xid is an XA transaction identifier. xid是XA事务标识符。It indicates which transaction the statement applies to. 它指示该语句适用于哪个事务。xid values are supplied by the client, or generated by the MySQL server. xid值由客户端提供，或由MySQL服务器生成。An xid value has from one to three parts:xid值由一到三部分组成：
xid:gtrid[,bqual[,formatID]]
gtrid is a global transaction identifier, bqual is a branch qualifier, and formatID is a number that identifies the format used by the gtrid and bqual values. gtrid是全局事务标识符，bqual是分支限定符，formatID是标识gtrid和bqual值使用的格式的数字。As indicated by the syntax, 如语法所示，bqual and formatID are optional. bqual和formatID是可选的。The default 如果未给定，则默认bqual value is '' if not given. bqual值为''。The default 如果未给定，则默认formatID value is 1 if not given.formatID值为1。
gtrid and bqual must be string literals, each up to 64 bytes (not characters) long. gtrid和bqual必须是字符串文字，每个文字的长度不得超过64字节（不是字符）。gtrid and bqual can be specified in several ways. gtrid和bqual可以用几种方式指定。You can use a quoted string (您可以使用带引号的字符串（'ab'), hex string (X'6162', 0x6162), or bit value (b').nnnn''ab'）、十六进制字符串（X'6162'、0x6162）或位值（b'nnnn'）。
formatID is an unsigned integer.formatID是一个无符号整数。
The gtrid and bqual values are interpreted in bytes by the MySQL server's underlying XA support routines. gtrid和bqual值由MySQL服务器的底层XA支持例程以字节为单位进行解释。However, while an SQL statement containing an XA statement is being parsed, the server works with some specific character set. 但是，当解析包含XA语句的SQL语句时，服务器会处理某些特定的字符集。To be safe, write 为了安全起见，将gtrid and bqual as hex strings.gtrid和bqual写为十六进制字符串。
xid values typically are generated by the Transaction Manager. xid值通常由事务管理器生成。Values generated by one TM must be different from values generated by other TMs. 一个TM生成的值必须不同于其他TM生成的值。A given TM must be able to recognize its own 给定的TM必须能够在xid values in a list of values returned by the XA RECOVER statement.XA RECOVER语句返回的值列表中识别自己的xid值。
XA START starts an XA transaction with the given xidxid value. XA START 使用给定的xidxid值来启动一个XA事务。Each XA transaction must have a unique 每个XA事务必须具有唯一的xid value, so the value must not currently be used by another XA transaction. xid值，因此该值当前不能由另一个XA事务使用。Uniqueness is assessed using the 使用gtrid and bqual values. gtrid和bqual值评估唯一性。All following XA statements for the XA transaction must be specified using the same 必须使用与xid value as that given in the XA START statement. XA START语句中给定值相同的xid值指定XA事务的所有以下XA语句。If you use any of those statements but specify an 如果使用这些语句中的任何一条，但指定的xid value that does not correspond to some existing XA transaction, an error occurs.xid值与某些现有XA事务不对应，则会发生错误。
One or more XA transactions can be part of the same global transaction. 一个或多个XA事务可以是同一全局事务的一部分。All XA transactions within a given global transaction must use the same 给定全局事务中的所有XA事务必须在gtrid value in the xid value. xid值中使用相同的gtrid值。For this reason, 出于这个原因，gtrid values must be globally unique so that there is no ambiguity about which global transaction a given XA transaction is part of. gtrid值必须是全局唯一的，这样就不会对给定XA事务属于哪个全局事务产生歧义。The 对于全局事务中的每个XA事务，bqual part of the xid value must be different for each XA transaction within a global transaction. xid值的bqual部分必须不同。(The requirement that （要求bqual values be different is a limitation of the current MySQL XA implementation. It is not part of the XA specification.)bqual值不同是当前MySQL XA实现的一个限制。它不是XA规范的一部分。）
The XA RECOVER statement returns information for those XA transactions on the MySQL server that are in the PREPARED state. XA RECOVER语句返回MySQL服务器上处于PREPARED状态的XA事务的信息。(See Section 13.3.8.2, “XA Transaction States”.) （请参阅第13.3.8.2节，“XA事务状态”。）The output includes a row for each such XA transaction on the server, regardless of which client started it.输出包括服务器上每个此类XA事务的一行，而不管是哪个客户端启动的。
XA RECOVER requires the XA_RECOVER_ADMIN privilege. XA RECOVER需要XA_RECOVER_ADMIN权限。This privilege requirement prevents users from discovering the XID values for outstanding prepared XA transactions other than their own. 此权限要求防止用户发现自己事务以外的未完成准备XA事务的XID值。It does not affect normal commit or rollback of an XA transaction because the user who started it knows its XID.它不会影响XA事务的正常提交或回滚，因为启动它的用户知道它的XID。
XA RECOVER output rows look like this (for an example xid value consisting of the parts 'abc', 'def', and 7):XA RECOVER输出行如下所示（例如，由'abc'、'def'和7部分组成的xid值）：
mysql> XA RECOVER;
+----------+--------------+--------------+--------+
| formatID | gtrid_length | bqual_length | data |
+----------+--------------+--------------+--------+
| 7 | 3 | 3 | abcdef |
+----------+--------------+--------------+--------+
The output columns have the following meanings:输出列具有以下含义：
formatID is the formatID part of the transaction xidformatID是事务xid的formatID部分
gtrid_length is the length in bytes of the gtrid part of the xidgtrid_length是xid的gtrid部分的长度（以字节为单位）
bqual_length is the length in bytes of the bqual part of the xidbqual_length是xid的bqual部分的长度（以字节为单位）
data is the concatenation of the gtrid and bqual parts of the xiddata是xid的gtrid和bqual部分的串联
XID values may contain nonprintable characters. XID值可能包含不可打印的字符。XA RECOVER permits an optional CONVERT XID clause so that clients can request XID values in hexadecimal.XA RECOVER允许一个可选的CONVERT XID子句，以便客户端可以请求十六进制的XID值。