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Preview Sql.Cn

docs/document/content/user-manual/shardingsphere-proxy/distsql/syntax/rul/preview-sql.cn.md

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+++ title = "PREVIEW SQL" weight = 3 +++

描述

PREVIEW SQL 语法用于预览 SQL 执行计划。

语法

{{< tabs >}} {{% tab name="语法" %}}

sql
PreviewSql ::=
  'PREVIEW' sqlStatement 

{{% /tab %}} {{% tab name="铁路图" %}}

<iframe frameborder="0" name="diagram" id="diagram" width="100%" height="100%"></iframe> {{% /tab %}} {{< /tabs >}}

返回值说明

说明
data_source_name存储单元名称
actual_sql实际执行 SQL 语句

示例

  • 预览 SQL 执行计划
sql
PREVIEW SELECT * FROM t_order;
sql
mysql> PREVIEW SELECT * FROM t_order;
+------------------+-----------------------+
| data_source_name | actual_sql            |
+------------------+-----------------------+
| su_1             | SELECT * FROM t_order |
+------------------+-----------------------+
1 row in set (0.18 sec)

保留字

PREVIEW

相关链接