If you have successfully created the table, you can see the table you have created as shown below. Note: There are other options or variables available while you create a table, like setting primary or foreign key. But for the sake simplicity, we kept those options out of the scope of t...
直观起见我们依旧通过举例说明,下面通过CREATE TABLE LIKE来完成复制:create table t_key_event_file_student_101 (like t_key_event_file_student); 复制成功后再看一下表结构的DDL语句和数据: 如上图,同CREATE TABLE AS不同的是这次复制成功拷贝了所有NOT-NULL约束,并且没有拷贝表数据,这也渐渐...
test-# \c test;您现在已经连接到数据库"test",用户"postgres".test-# drop table company; test=# drop table company;DROP TABLEtest=# \d 查看删除后的目录结构 由于我一开始只有一张company; 删除后, 显示没有其他的表 更改表数据 比如我这里有一张pg_equipment的表 2. 插入记录 2.1 语法 PostgreSQL ...
create table t_key_event_file_student_101 (like t_key_event_file_student); 复制成功后再看一下表结构的DDL语句和数据: 如上图,同CREATE TABLE AS不同的是这次复制成功拷贝了所有NOT-NULL约束,并且没有拷贝表数据,这也渐渐接近了我们的需求,并且验证了一点,就是CREATE TABLE LIKE并不会复制任何数据,而CRE...
首先看看CREATE TABLE AS的用法,在这之前结合一个具体的例子看看,我们需要复制的是这样一张表: 如上图所示,在PowerDesigner的物理模型(pdm)中我们可以看到这张表定义了主键和一个外键,再看看它的ddl语句: droptablet_key_event_file_student;/*===*//* Table: t_key_event_file_student *//*===*/create...
postgres=# Second, connect to the dvdrental database: \c dvdrental Third, enter the following CREATE TABLE statement and press Enter: CREATE TABLE accounts ( user_id SERIAL PRIMARY KEY, username VARCHAR (50) UNIQUE NOT NULL, password VARCHAR (50) NOT NULL, email VARCHAR (255) UNIQUE NOT ...
table_name The name (optionally schema-qualified) of the table to create. column_name The name of a column to create in the new table. data_type The data type of the column. This can include array specifiers. For more information on the data types included with EDB Postgres...
postgres=# drop database testdb; DROP DATABASE postgres=# 1. 2. 3. 4. 创建表 创建表之前要连接指定的数据库 \c test; CREATE TABLE table_name( column1 datatype, column2 datatype, column3 datatype, ... columnN datatype, PRIMARY KEY( one or more columns ) );...
using Npgsql; // Construct CREATE TABLE statements var statements = new List<string> {@" CREATE TABLE courses( id INT GENERATED ALWAYS AS IDENTITY PRIMARY KEY, name VARCHAR(255) NOT NULL UNIQUE, duration INTERVAL NOT NULL, description TEXT )", @"CREATE TABLE students( id INT GENERATED ALWAYS...
The out of line method of declaring a primary key in a Create Table command is a bit different. CREATEtable_name(column_name data_type,...CONSTRAINTpk_tbl1PRIMARYKEY(column_name)); You need to add it after all of your column definitions. You also need to start with the word CONSTRAINT...