Support more s3option for stage

docs/MatrixOne/Reference/SQL-Reference/Data-Definition-Language/1.1-create-stage.md

@@ -0,0 +1,86 @@
+# **CREATE STAGE**
+
+## **Description**
+
+The `CREATE STAGE` command is used in the MatrixOne database to create a named internal or external data stage for **data export**. By creating a data stage and exporting data to it, you can download data files to your local system or store them in cloud storage services.
+
+- **Internal Stage**: Internal stages store data files within the MatrixOne system. Internal stages can be either permanent or temporary.
+
+- **External Stage**: External stages reference data files stored outside the MatrixOne environment. Currently, the following cloud storage services are supported:
+
+    - Amazon S3 buckets
+    - Aliyun buckets
+
+The storage location can be private/protected or public—however, data held in archival cloud storage classes that require restoration before retrieval cannot be accessed.
+
+An internal or external stage can include a directory table. Directory tables maintain a catalog of staged file directories in cloud storage.
+
+- Configure a specified path to control the write permissions for user `SELECT INTO` operations. After creation, users can only write to the set `STAGE` path.
+
+- If no `STAGE` is created or all `STAGE` instances are `DISABLED`, users can write to any path permitted by the operating system or object storage permissions.
+
+- If not using a `STAGE`, users must forcefully include `credential` information during `SELECT INTO` operations.
+
+!!! note
+    1. Cluster administrators (i.e., root users) and tenant administrators can create data stages.
+    2. Once created, data tables can only be imported to the paths specified in the STAGE.
+
+## **Syntax**
+
+```
+> CREATE STAGE [ IF NOT EXISTS ] { stage_name }
+   { StageParams }
+   [ directoryTableParams ]
+   [ COMMENT = '<string_literal>' ]
+
+StageParams (for Amazon S3) :
+URL =  "endpoint"='<string>' CREDENTIALS = {"access_key_id"='<string>', "secret_access_key"='<string>', "filepath"='<string>', "region"='<string>'}
+
+StageParams (for Aliyun OSS) :
+URL =  "endpoint"='<string>' CREDENTIALS = {"access_key_id"='<string>', "secret_access_key"='<string>'}
+
+StageParams (for File System) :
+URL= 'filepath'
+
+directoryTableParams :
+ENABLE = { TRUE | FALSE }
+```
+
+### Explanations
+
+- `IF NOT EXISTS`: An optional parameter used to check whether a stage with the same name already exists when creating a stage, avoiding duplicate creations.
+
+- `stage_name`: The name of the stage to be created.
+
+- `StageParams`: This parameter group is used to specify the stage's configuration parameters.
+
+    - `endpoint`: The connection URL for the stage, indicating the location of the object storage service. This URL's content may vary for object storage services like Amazon S3, Aliyun OSS, or a file system. For example s3.us-west-2.amazonaws.com
+
+    - `CREDENTIALS`: This JSON object contains the credentials required to connect to the object storage service.
+
+        + `access_key_id`: Access key ID used for authentication.
+        + `secret_access_key`: Key associated with the access key ID for authentication.
+        + `"filepath"='<string>'`: Specifies the file path or directory in the S3 storage.
+        + `"region"='<string>'`: Specifies the AWS region where the Amazon S3 storage is located.
+
+- `directoryTableParams`: This parameter group is used to specify the configuration of a directory table associated with the stage.
+
+    - `ENABLE`: Indicates whether the directory table is enabled, with values `TRUE` or `FALSE` values.
+
+## **Examples**
+
+```sql
+CREATE TABLE `user` (`id` int(11) ,`user_name` varchar(255) ,`sex` varchar(255));
+INSERT INTO user(id,user_name,sex) values('1', 'weder', 'man'), ('2', 'tom', 'man'), ('3', 'wederTom', 'man');
+
+-- Create internal data stage
+mysql> CREATE STAGE stage1 URL='/tmp' ENABLE = TRUE;
+
+-- Export data from the table to data stage
+mysql> SELECT * FROM user INTO OUTFILE 'stage1:/user.csv';
+-- You can see your exported table in your local directory
+
+-- After setting the data stage, the data table can only be exported to the specified path, and an error will be reported when exporting to other paths
+mysql> SELECT * FROM user INTO OUTFILE '~/tmp/csv2/user.txt';
+ERROR 20101 (HY000): internal error: stage exists, please try to check and use a stage instead
+```