Orientdb 简明教程
OrientDB - Alter Database
数据库是一个包含不同属性的重要数据模型，可以根据自己的要求对其进行修改。
Database is a one of the important data models with different attributes that you can modify as per your requirements.
以下语句是 Alter Database 命令的基本语法。
The following statement is the basic syntax of the Alter Database command.
ALTER DATABASE <attribute-name> <attribute-value>其中 <attribute-name> 定义要修改的属性， <attribute-value> 定义要为此属性设置的值。
Where <attribute-name> defines the attribute that you want to modify and <attribute-value> defines the value you want to set for that attribute.
下表定义了用于修改数据库的支持属性列表。
The following table defines the list of supported attributes for altering a database.
Sr.No. |
Attribute Name |
Description |
1 |
STATUS |
Defines the database’s status between different attributes. |
2 |
IMPORTING |
Sets the importing status. |
3 |
DEFAULTCLUSTERID |
Sets the default cluster using ID. By default it is 2. |
4 |
DATEFORMAT |
Sets the particular date format as default. By default it is "yyyy-MM-dd". |
5 |
DATETIMEFORMAT |
Sets the particular date time format as default. By default it is "yyyy-MM-dd HH:mm:ss". |
6 |
TIMEZONE |
Sets the particular time zone. By default it is Java Virtual Machine’s (JVM’s) default time zone. |
7 |
LOCALECOUNTRY |
Sets the default locale country. By default it is JVM’s default locale country. For example: "GB". |
8 |
LOCALELANGUAGE |
Sets the default locale language. By default it is JVM’s default locale language. For example: "en". |
9 |
CHARSET |
Sets the type of character set. By default it is JVM’s default charset. For example: "utf8". |
10 |
CLUSTERSELECTION |
Sets the default strategy used for selecting the cluster. These strategies are created along with the class creation. Supported strategies are default, roundrobin, and balanced. |
11 |
MINIMUMCLUSTERS |
Sets the minimum number of clusters to create automatically when a new class is created. By default it is 1. |
12 |
CUSTOM |
Sets the custom property. |
13 |
VALIDATION |
Disables or enables the validations for entire database. |
Example
从 OrientDB-2.2 版本开始，添加了新的 SQL 解析器，在某些情况下不允许使用常规语法。因此，在某些情况下，我们必须禁用新的 SQL 解析器 (StrictSQL)。你可以使用以下 Alter database 命令禁用 StrictSQL 解析器。
From the version of OrientDB-2.2, the new SQL parser is added which will not allow the regular syntax in some cases. Therefore, we have to disable the new SQL parser (StrictSQL) in some cases. You can use the following Alter database command to disable the StrictSQL parser.
orientdb> ALTER DATABASE custom strictSQL = false如果命令执行成功，则会得到以下输出。
If the command is executed successfully, you will get the following output.
Database updated successfully