if not exists

1. Via Hive ViewCREATE EXTERNAL TABLE if not exists finance.json_serde_optd_table (RetCode string, retmsg string, data array>) ROW FORMAT SERDE ' org.apache.hive.hcatalog.data.JsonSerDe ' location ' hdfs://wdp.xxxxx.cn : 8020/nifi/finance1/optd/';

First, create the data table: The syntax rules and usage of this command are essentially the same as most relational databases, so we illustrate the various rules for creating tables in SQLite. However, for some sqlite-specific rules, we will give

(i) Common SQL statements1.SELECT user () get logged in2.SELECT version () get MySQL release information3.SELECT now () get the current time4.SELECT database () Gets the name of the open databases(ii) database-related operations1. Create a database (

CREATE TABLE ' Student ' (' Studentno ' INT (4) Not NULL PRIMARY KEY COMMENT ' study number ',' Loginpwd ' VARCHAR (not NULL COMMENT ' password '),' Studentname ' VARCHAR (a) not NULL COMMENT ' name ',' Sex ' CHAR (2) Not NULL DEFAULT ' male '

First, let's talk about why the tables are divided.When a piece of data reaches millions of, you spend more time searching for it, and if you have a joint query, I think it's possible to die there. The purpose of the sub-table is to reduce the

In my conscience, I can't tell you not to use core Data. It's good, and it's getting better, and it's been understood by many other cocoa developers that it's important to have new people join your group or need someone to take over your

Ext: http://segmentfault.com/a/1190000000363392 Editor's note: The article "I" refers to the original author.In my conscience, I can't tell you not to use core Data. It's good, and it's getting better, and it's been understood by many other cocoa

Customize a backup script based on your environment! Description How to use: Exec master.dbo.fullbackup1 ' s:\backup ', ' Suzhou ', ' full ' 0. Backup type can only be full, diff or log, database name cannot be empty 1. Record each backup by

1. Foreground function---home---brand page---product details---product review management---shopping cart management---billing page---user login and exit---personal center management---order submission page2. Background function---landing

manipulating Databases1. Create a databasesyntax : CREATE database name ;2. View the list of databasessyntax : SHOW DATABASE;3. Select a databasesyntax : Use database name ;4. Deleting a databasesyntax : DROP database name ; manipulating data tables

I. Basic creation Operation: 1. Create a table CREATE TABLE IF not EXISTS t_dog (name text, age Bolb, weight real); 2. Inserting records INSERT into T_shop (name, Left_count) VALUES (' fan ', 100); 3. Modify the

 MySQLCreate data table (medium)Third, data field properties1 , unsigned "Unsigned"You can increase the space by a factor of -128~127 to 0 , for example . ~ 255Note: Can only be used in numeric fields2 , Zerofill "Leading 0"e.g. createtable if

The following command lines are used in Windows 64-bit operating systems. Before learning, Let's explain the meanings of some symbols in the MySQL Syntax: (1) brackets ([]) indicate that both exist or do not exist. They are optional parameters. For

From: http://www.2cto.com/database/201206/134514.html 0. Create a database tableMysql> create database if not exists my_db default charset utf8 COLLATE utf8_general_ci;# Pay attention to the following sentence "COLLATE utf8_general_ci", which

Php implements simple ACL. The copy code is as follows: -- ACLTables -- table structure 'aclresources' droptableifexists' aclresources'; CREATETABLEIFNOTEXISTS 'aclresources' ('rsid 'varchar (64) NOTNULL The code is as follows: -- ACL Tables--

This article mainly introduces how to create and use temporary tables in MySQL. pay attention to the data clearing problem in temporary tables. if you need to clear temporary tables, refer to when you are working on a very large table, you may

MySQL study NOTE _ 3_MySQL create a data table (in) bitsCN. comMySQL create a data table (in) III. data field attributes 1. unsigned [unsigned] Space can be doubled, for example,-128 ~ 127 increase to 0 ~ 255 Note: only numeric fields can be used. 2.

Copy CodeThe code is as follows: --ACL Tables --The structure of the table ' Aclresources ' DROP TABLE IF EXISTS ' aclresources '; CREATE TABLE IF not EXISTS ' aclresources ' ( ' Rsid ' varchar (+) not NULL, ' Access ' int (4) is not NULL for

Basic operations for mysql Data Tables: Table Structure operations, field operations, and basic mysql operationsThis section introduces:  Table Structure operations Create a data table, View data tables and View fields, Modify data table

MySQL study note _ 3_MySQL create a data table (medium)Creating a data table in MySQL 3. Data field attributes 1. unsigned [unsigned] Space can be doubled, for example,-128 ~ 127 increase to 0 ~ 255 Note: Only numeric fields can be used. 2. zerofill