CREATE TABLE – SQL Command项目 2006/10/23 Creates a table having the specified fields. 复制 CREATE TABLE | DBF TableName1 [NAME LongTableName] [FREE] (FieldName1 FieldType [(nFieldWidth [, nPrecision])] [NULL | NOT NULL] [CHECK lExpression1 [ERROR cMessageText1]] [DEFAULT e...
Visual FoxPro uses the default value if you use the SQL ALTER TABLEcommand to remove autoincrementing for the field.PRIMARY KEY | UNIQUE PRIMARY KEY creates a primary index for the field specified in FieldName1. UNIQUE creates a candidate index for the field specified in FieldName1. The ...
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...
Here, the SQL command checks if a table namedCompaniesexists, and if not, it creates a table with specified columns. Create Table Using Another Existing Table In SQL, we can create a new table by duplicating an existing table's structure. Let's look at an example. -- create a backup t...
This topic provides an explanation of the SQL grammar that is used for the CREATE EXTERNAL TABLE command.
( Using Command Lines ) If you prefer you can also run commands from a command line to create a table. A lot of web hosts don't give you shell access to the server anymore, or allow remote access to the MySQL servers. If you want to do it this way you may have to install MySQL...
command.Connection=newSqlConnection(connStr);//第三步:创建SqlDataAdapterSqlDataAdapter adapter =newSqlDataAdapter(command);//第四步:创建DataSet和DataTableDataSet dataSet =newDataSet(); DataTable dataTable=newDataTable();//第五步:填充数据adapter.Fill(dataTable); ...
CREATETRIGGERtriggername BEFORE|AFTERINSERT|UPDATE|DELETE ONtablenameFOREACHROW statement_list 触发时间如下: BEFORE指在检查约束前触发。 AFTER指在检查约束后触发。 触发器只能创建在永久表上,不能对临时表创建触发器。对同一个表相同触发时间的相同触发事件,只能定义一个触发器。
empty_lobs_are_null--setempty LOBs tonull(DefaultFALSE)defaults--direct pathdefaultvalue loading;EVALUATE_ONCE,EVALUATE_EVERY_ROW,IGNORE,IGNORE_UNSUPPORTED_EVALUATE_ONCE,IGNORE_UNSUPPORTED_EVALUATE_EVERY_ROWdirect_path_lock_wait--waitforaccess to table when currentlylocked(DefaultFALSE)PLEASENOTE:Command-...
KSQL 是基于 Kafka 的 Streams API 进行构建的,所以它的两个核心概念是流(Stream)和表(Table)。 流是没有边界的结构化数据,数据可以被源源不断地添加到流当中,但流中已有的数据是不会发生变化的,即不会被修改也不会被删除。 代码语言:javascript 代码运行次数:0 运行 AI代码解释 CREATE STREAM pageviews (vi...