mybatis-plus批量插入生效條件和源碼分析

mybatis-plus批量插入生效條件和源碼分析

代碼

com.baomidou.mybatisplus.extension.service.IService#saveBatch(java.util.Collection<T>)

源碼實現

可以看到使用的是ExecutorType.BATCH執行器

mybatis中BATCH執行器源碼

如圖可以看到使用的是JDBC底層的addBatch方法，最后flush中調用executeBatch真正開始執行

JDBC層（mysql-connector-java:8）

protected long[] executeBatchInternal() throws SQLException {
        synchronized (checkClosed().getConnectionMutex()) {
            if (this.connection.isReadOnly()) {
                throw new SQLException(Messages.getString("PreparedStatement.25") + Messages.getString("PreparedStatement.26"),
                        MysqlErrorNumbers.SQL_STATE_ILLEGAL_ARGUMENT);
            }
            if (this.query.getBatchedArgs() == null || this.query.getBatchedArgs().size() == 0) {
                return new long[0];
            }

            // we timeout the entire batch, not individual statements
            int batchTimeout = getTimeoutInMillis();
            setTimeoutInMillis(0);
            resetCancelledState();

            try {
                statementBegins();
                clearWarnings();
                //batch不包含sql字符串，並且開啟rewriteBatchedStatements
                if (!this.batchHasPlainStatements && this.rewriteBatchedStatements.getValue()) {
                    //判斷是否可以改寫為mutil-value insert
                    if (((PreparedQuery<?>) this.query).getParseInfo().canRewriteAsMultiValueInsertAtSqlLevel()) {
                        return executeBatchedInserts(batchTimeout);
                    }
                    //batch數量大於3，通過multi statement執行sql
                    if (!this.batchHasPlainStatements && this.query.getBatchedArgs() != null
                            && this.query.getBatchedArgs().size() > 3 /* cost of option setting rt-wise */) {
                        return executePreparedBatchAsMultiStatement(batchTimeout);
                    }
                }
                //順序執行
                return executeBatchSerially(batchTimeout);
            } finally {
                this.query.getStatementExecuting().set(false);

                clearBatch();
            }
        }
    }

如上代碼注釋批量執行的基本條件要開啟rewriteBatchedStatements並且沒有plain sql