Write a SQL query to create a table with three columns: id, name, and age. Add a primary key constraint on the id column. Write a SQL query to create a table with four columns: product_id, product_name, price,
FOREIGN KEY: The foreign key is a column that creates a link between two tables. The foreign key of any table refers to the Primary Key of another table. A table can have one or more foreign keys. A foreign key constraint prevents the UPDATE and DELETE statement that breaks the link bet...
CREATE [ [ GLOBAL | LOCAL ] { TEMPORARY | TEMP } | UNLOGGED ] TABLE [ IF NOT EXISTS ] table_name { ({ column_name data_type [ compress_mode ] [ COLLATE collation ] [ column_constraint [ ... ] ] | table_constraint | LIKE source_table [ like_option [...] ] } [, ... ]...
%msg&sql(CREATEGLOBALTEMPORARYTABLETempEmp(EMPNUMINTNOTNULL,NAMELASTCHAR(30)NOTNULL,NAMEFIRSTCHAR(30)NOTNULL,CONSTRAINTEMPLOYEEPKPRIMARYKEY(EMPNUM)))ifSQLCODE=0{w!,"表创建"}else{w!,"SQLCODE=",SQLCODE,": ",%msg}}
CREATE EXTERNAL TABLE 支持配置列名、数据类型、为 Null 性和排序规则的功能。 不能对外部表使用 DEFAULT CONSTRAINT。 列定义(包括数据类型和列数)必须与外部文件中的数据匹配。 如果存在不匹配,则在查询实际数据时会拒绝文件行。 LOCATION = “folder_or_filepath” ...
= column_set_name XML COLUMN_SET FOR ALL_SPARSE_COLUMNS <table_constraint> ::= [ CONSTRAINT constraint_name ] { { PRIMARY KEY | UNIQUE } [ CLUSTERED | NONCLUSTERED ] ( column_name [ ASC | DESC ] [ ,... n ] ) [ WITH FILLFACTOR = fillfactor | WITH ( <index_option> [ ,... ...
To create a table with a primary key, we can write the following command. In MySQL CREATETABLECompanies (idint,namevarchar(50), addresstext, emailvarchar(50), phonevarchar(10), PRIMARYKEY(id) ); In Oracle and SQL Server CREATETABLECompanies (idintNOTNULLPRIMARYKEY,namevarchar(50), ...
= column_set_name XML COLUMN_SET FOR ALL_SPARSE_COLUMNS <table_constraint> ::= [ CONSTRAINT constraint_name ] { { PRIMARY KEY | UNIQUE } [ CLUSTERED | NONCLUSTERED ] ( column_name [ ASC | DESC ] [ ,... n ] ) [ WITH FILLFACTOR = fillfactor | WITH ( <index_option> [ ,... ...
第十五章 SQL命令 CREATE TABLE(二) 全局临时表 指定GLOBAL TEMPORARY关键字将表定义为全局临时表。表定义是全局的(对所有进程都可用);表数据是临时的(在进程期间持续存在)。相应的类定义包含一个附加的类参数SQLTABLETYPE=“GLOBAL TEMPORARY”。与标准的 IRIS表一样,ClassType=Persistent,并且类包含Final关键字,表...
Drop Table Truncate Table Create Table 创建表 CREATE [TEMPORARY] [EXTERNAL] TABLE [IF NOT EXISTS] [db_name.]table_name -- (Note: TEMPORARY available in Hive 0.14.0 and later) [(col_name data_type [COMMENT col_comment], ... [constraint_specification])] ...