解析 D 正确答案:D 解析:选项A)是创建一个新的对象,例如一个表;选项B)用来向表中追加记录,它是非SQL命令;在SQL的ALTER TABLE语句中,可以使用ADD[COLUMN]短语来增加一个新的字段。其中,COLUMN短语表示“列”,可以省略。 知识模块:关系数据库标准语言SQL反馈 收藏
In this case, we can also use CREATE TABLE to make a copy of the table structure so we do not need to type all the column names, data types, and constraints in detail. The syntax for doing this is: CREATE TABLE "table_name" AS [SQL Statement]; ...
If you create a new table using an existing table, the new table will be filled with the existing values from the old table. Syntax CREATETABLEnew_table_nameAS SELECTcolumn1, column2,... FROMexisting_table_name WHERE...; The following SQL creates a new table called "TestTable" (which...
table_nameis name of the table you want to create columnis the name of a column in the table datatypeis the type of data that the column can hold (e.g., integer, varchar, date) Example: SQL CREATE TABLE -- create a table Students with different columnsCREATETABLEStudents(idint,nameva...
簡單CREATE TABLE 語法 (如果沒有使用選項則通用): syntaxsql 複製 CREATE TABLE { database_name.schema_name.table_name | schema_name.table_name | table_name } ( { <column_definition> } [ ,... n ] ) [ ; ] 完整語法 磁碟型 CREATE TABLE 語法: syntaxsql ...
Simple CREATE TABLE syntax (common if not using options): syntaxsql Copy CREATE TABLE { database_name.schema_name.table_name | schema_name.table_name | table_name } ( { <column_definition> } [ ,... n ] ) [ ; ] Full syntax Disk-based CREATE TABLE syntax: syntaxsql Copy CREATE...
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 [...] ] } [, ... ]...
The ALTER TABLE command adds, deletes, or modifies columns in a table.The ALTER TABLE command also adds and deletes various constraints in a table.The following SQL adds an "Email" column to the "Customers" table:Example ALTER TABLE CustomersADD Email varchar(255); Try it Yourself » ...
CREATE[TEMPORARY]TABLE[IFNOTEXISTS] tbl_name [(create_definition,...)] [table_options] [partition_options] [IGNORE|REPLACE] [AS] query_expression 3.简单SQL表明结构: 1 CREATETABLEt7liket1; 格式: 1 CREATE[TEMPORARY]TABLE[IFNOTEXISTS] tbl_name {LIKEold_tbl_name | (LIKEold_tbl_name) } ...
[table_options] [partition_options] [IGNORE | REPLACE] [AS] query_expression CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name { LIKE old_tbl_name | (LIKE old_tbl_name) } create_definition: { col_name column_definition | {INDEX | KEY} [index_name] [index_type] (key_part,...) ...