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...
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...
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...
command CREATE TABLE – SQL Command Creates a table having the specified fields. CREATE TABLE | DBF TableName1 [NAME LongTableName] [FREE] (FieldName1 FieldType [(nFieldWidth [, nPrecision])] [NULL | NOT NULL] [CHECK lExpression1 [ERROR cMessageText1]] [DEFAULT eExpression1] [PRIMARY...
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, ...
CREATE TABLE 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 (...
The SQL CREATE TABLE command is used as follows. SQL CREATE TABLE Statement Syntax CREATE TABLE <table_name> ( <column_name1> <datatype1> <constraint1> <column_name2> <datatype2> <constraint2> <constraint-list> ) The number of characters that can make up SQL table names and ...
->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...