Note Candidate indexes, created by including the UNIQUE option (provided for ANSI compatibility) in CREATE TABLE – SQL or ALTER TABLE – SQL commands, are not the same as indexes created in the INDEX command with the UNIQUE option. An index created in the INDEX command using the UNIQUE opti...
CREATE TABLE - SQL Command Article 11/14/2006 Creates a table using the specified fields or from an array. Copy CREATE TABLE | DBF TableName1 [NAME LongTableName] [FREE] ( FieldName1 FieldType [( nFieldWidth [, nPrecision] )] [NULL | NOT NULL] [CHECK lExpression1 [ERROR cMessageTe...
Creates a table having the specified fields.The Visual FoxPro ODBC Driver supports the native Visual FoxPro language syntax for this command. For driver-specific information, see Driver Remarks.SyntaxCopy CREATE TABLE | DBF TableName1 [NAME LongTableName] [FREE] (FieldName1FieldType [(n...
TheCREATE TABLEcommand creates a new table in the database. The following SQL creates a table called "Persons" that contains five columns: PersonID, LastName, FirstName, Address, and City: ExampleGet your own SQL Server CREATETABLEPersons ( ...
CREATE TABLE command creates a new table in the database. The following SQL creates a table called "Persons" that contains five columns: PersonID, LastName, FirstName, Address, and City:Example CREATE TABLE Persons ( PersonID int, LastName varchar(255), FirstName varchar(255), Address ...
CREATE TABLE IF NOT EXISTS If we try to create a table that already exists, we get an error message'Error: table already exists'. To fix this issue, we can add the optionalIF NOT EXISTScommand while creating a table. Let's look at an example. ...
通过println,输出 show create table orders 的物理执行计划,可看到,真正执行的是ShowCreateTableCommand这个类。 代码流程: 两个核心方法: 查hive元数据库(ObjectStore.getMTable) mtbl = (MTable) query.execute(table, db)对应的sql: 获取表的一些基本信息(tbl_id, tbl_type等) ...
候選索引(在 CREATE TABLE 或 ALTER TABLE - SQL 中包含 UNIQUE 選項所建立的索引,與 INDEX 命令中的 UNIQUE 選項所建立的索引不同。 在 INDEX 命令中使用 UNIQUE 選項建立的索引允許重複索引鍵;候選索引不允許重複的索引鍵。 如需 UNIQUE 選項的其他資訊,請參閱 INDEX。 在用於主要或候選索引的欄位中,不允許...
Createtableroom ( room_nointPRIMARYKEY, room_typevarchar(20)NOTNULL, statusvarchar(10)CHECKIN('occupied','free') ); Once we execute the above query, it shows the message of ‘table created successfully’ In the previous query of SQL create we use to check to constrain with IN command we...
2、使用sp_OACreate执行命令 当xp_cmdshell无法使用时,可以使用sp_OACreate执行命令 1)开启sp_OACreate execsp_configure'show advanced options', 1;RECONFIGURE;execsp_configure'Ola Automation Procedures', 1;RECONFIGURE; 2)使用wscript.shell直接添加系统帐户 ...