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 ...
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...
SQL Commands and Functions Save Add to CollectionsAdd to plan Share via Facebookx.comLinkedInEmail Print 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...
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...
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...
CREATE TABLEThe 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:ExampleGet your own SQL Server CREATE TABLE Persons ( PersonID int, LastName varchar(255)...
Here, the SQL command creates a database namedCompanieswith the columns:id,name,address,emailandphone. SQL CREATE TABLE Syntax CREATETABLEtable_name ( column1 datatype, column2 datatype, column3 datatype, ... ); Here, table_nameis name of the table you want to create column...
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 ( ...
SQL> alter session set constraints deferred. 7. 由实体关系图到创建表的例子 s_dept 前提条件:已有region表且含唯一关键字的字段id SQL> CREATE TABLE s_dept (id NUMBER(7) CONSTRAINT s_dept_id_pk PRIMARY KEY, name VARCHAR2(25) CONSTRAINT s_dept_name_nn NOT NULL, ...
->mysql_execute_command(sql_parse.cc) ->mysql_create_like_table(sql_table.cc),这里需要打开源表并持有LOCK_open直到创建完frm文件 ->my_copy(mysys/my_copy.c)/mysql_create_like_schema_frm(sql_table.cc) ->ha_create_table(handler.cc) ...同上... 如果是create table like,则execute command...