pingcap · sre-bot · May 25, 2020 · May 25, 2020 · May 25, 2020 · May 25, 2020
diff --git a/media/sqlgram/ColumnName.png b/media/sqlgram/ColumnName.png
diff --git a/media/sqlgram/CreateDatabaseStmt.png b/media/sqlgram/CreateDatabaseStmt.png
diff --git a/media/sqlgram/CreateIndexStmtUnique.png.bak b/media/sqlgram/CreateIndexStmtUnique.png.bak
diff --git a/media/sqlgram/DBName.png b/media/sqlgram/DBName.png
diff --git a/media/sqlgram/DatabaseOptionList.png b/media/sqlgram/DatabaseOptionList.png
diff --git a/media/sqlgram/DatabaseOptionListOpt.png b/media/sqlgram/DatabaseOptionListOpt.png
diff --git a/media/sqlgram/DeallocateStmt.png b/media/sqlgram/DeallocateStmt.png
diff --git a/media/sqlgram/DeallocateSym.png b/media/sqlgram/DeallocateSym.png
diff --git a/media/sqlgram/DropTableStmt.png b/media/sqlgram/DropTableStmt.png
diff --git a/media/sqlgram/Identifier.png b/media/sqlgram/Identifier.png
diff --git a/media/sqlgram/IfNotExists.png b/media/sqlgram/IfNotExists.png
diff --git a/media/sqlgram/IndexTypeOpt.png b/media/sqlgram/IndexTypeOpt.png
diff --git a/media/sqlgram/RestrictOrCascadeOpt.png b/media/sqlgram/RestrictOrCascadeOpt.png
diff --git a/media/sqlgram/TableNameList.png b/media/sqlgram/TableNameList.png
diff --git a/media/sqlgram/TableOrTables.png b/media/sqlgram/TableOrTables.png
diff --git a/sql-statements/sql-statement-alter-table.md b/sql-statements/sql-statement-alter-table.md
@@ -94,7 +94,7 @@ EXPLAIN SELECT * FROM t1 WHERE c1 = 3;
 
 ## MySQL 兼容性
 
-* 支持除空间类型外的所有数据类型。其它不支持的情况可参考：[alter-primary-key](/tidb-configuration-file.md#alter-primary-key)。
+* 支持除空间类型外的所有数据类型。其它不支持的情况可参考：[DDL 语句与 MySQL 的兼容性情况](/mysql-compatibility.md#ddl)。
 
 ## 另请参阅
 

diff --git a/sql-statements/sql-statement-change-column.md b/sql-statements/sql-statement-change-column.md
@@ -19,10 +19,6 @@ aliases: ['/docs-cn/dev/reference/sql/statements/change-column/']
 
 ![AlterTableSpec](/media/sqlgram/AlterTableSpec.png)
 
-**ColumnKeywordOpt:**
-
-![ColumnKeywordOpt](/media/sqlgram/ColumnKeywordOpt.png)
-
 **ColumnName:**
 
 ![ColumnName](/media/sqlgram/ColumnName.png)

diff --git a/sql-statements/sql-statement-create-database.md b/sql-statements/sql-statement-create-database.md
@@ -13,11 +13,7 @@ aliases: ['/docs-cn/dev/reference/sql/statements/create-database/']
 
 **CreateDatabaseStmt:**
 
-![CreateDatabaseStmt](/media/sqlgram/CreateDatabaseStmt.png)
-
-**DatabaseSym:**
-
-![DatabaseSym](/media/sqlgram/DatabaseSym.png)
+![CreateDaatabaseStmt](/media/sqlgram/CreateDatabaseStmt.png)
 
 **IfNotExists:**
 

diff --git a/sql-statements/sql-statement-drop-column.md b/sql-statements/sql-statement-drop-column.md
@@ -19,10 +19,6 @@ aliases: ['/docs-cn/dev/reference/sql/statements/drop-column/']
 
 ![AlterTableSpec](/media/sqlgram/AlterTableSpec.png)
 
-**ColumnKeywordOpt:**
-
-![ColumnKeywordOpt](/media/sqlgram/ColumnKeywordOpt.png)
-
 **ColumnName:**
 
 ![ColumnName](/media/sqlgram/ColumnName.png)
@@ -129,7 +125,8 @@ SELECT * FROM t1;
 
 ## MySQL 兼容性
 
-* 不支持使用相同语句删除多个列。
+* 目前不支持在一条语句中同时删除多个列。
+* 目前不支持删除主键列或索引列。
 
 ## 另请参阅
 

diff --git a/sql-statements/sql-statement-drop-table.md b/sql-statements/sql-statement-drop-table.md
@@ -90,6 +90,7 @@ Query OK, 0 rows affected (0.23 sec)
 ## MySQL 兼容性
 
 * 在尝试删除不存在的表时，使用 `IF EXISTS` 删除表不会返回警告。[Issue #7867](https://github.com/pingcap/tidb/issues/7867)
+* 目前 `RESTRICT` 和 `CASCADE` 仅在语法上支持。
 
 ## 另请参阅