SQL Intermediate Postgre. SQL, Subqueries and more If youre in the early phases of learning SQL and have completed one or more introductory level courses, youve probably learned most of the basic fundamentals and possibly even some high level database concepts. Selects data from a table or multiple tables. GROUP BY groups the the result by the given expressions. HAVING filter rows after grouping. ORDER BY sorts the result. Searching postgresqls email group archives for upsert leads to finding an example of doing what you possibly want to do, in the manual Example 382. PostgreSQL vs. MS SQL Server. A comparison of two relational databases from the point of view of a data analyst. Didnt see an example of both in one query. So this example might help. INTERNATIONALORDERS table of orders by company by location by day companyId, country. Learn how to work with SQL in more detail including setting up tables in PostgreSQL, views, subqueries and more. T Sql Update Group By Having Postgresql' title='T Sql Update Group By Having Postgresql' />Gives you clear, concise and easy to understand SQL tutorial with practical examples. You will learn how to write SQL query like a Pro. Brown Bird The Sound Of Ghosts Download more. Name. PostgreSQLs developers pronounce PostgreSQL as p o s t r s k ju l. It is abbreviated as Postgres because of ubiquitous support for. As you prepare to embark on the next phase of learning SQL, its important to not only understand SQL itself, but also the engine that makes it all possible the database. In most introductory level courses, youll typically use some sort of embedded database e. SQLite. Embedded databases are an excellent choice for beginners so that they can focus on learning SQL without the burden of allocating additional computing resources and mitigating the time to install configure the software. However, as the requirements of your application andor data begin to scale, you may need a more robust solution. At a high level, there are two main types of databases server based, and file based also called embedded. One of the most popular file based databases is SQLite. Its great for small scale applications, but as your needs become more complex it has many limitations. For example, its based on one large binary file thats limited to 1. If youre thinking that this is larger than anything youd ever need at least any time soon, youre probably right. However, many filesystems limit the maximum size of a file to something far less than this. So if you wanted to develop a large scale web application, this would not be feasible. Furthermore, there are security concerns, among many others. Server based databases provide key functionality to larger and more robust applications, like high availabilityfailover, increased and more flexible security, scalability, increased performance, and more. Today, were going to perform data discovery and analysis on two data sets from the Consumer Financial Protection Bureau CFPB using Postgre. SQL postgres. The data consists of consumer complaints regarding two types of financial services bank accounts and credit cards. First, well set up your database by creating tables, creating users, and loading the data from CSV files. Next, well dive into more advanced SQL concepts while analyzing the data and discovering valuable insights Some of the SQL concepts well be covering today are below. Creating users, databases and tables,The IS NULLIS NOT NULL clause,Views,Subqueries,Unionunion all,Intersectexcept,String concatenation, and. Casting data types. If you need to brush up on your SQL fundamentals, we recommend our blog post SQL Basics Working with Databases. Our data. Were going to be working with two different CSV files of consumer complaint data from the CFPB BankAccountorServiceComplaints. CreditCardComplaints. The files were originally downloaded from the CFPB website, however we have uploaded the versions using in this post as a which you can download here so you can use the exact file versions we used, since CFPB regularly update their data. Both CSV files have identical fields. Below is each field, and the data type The table below consists of the data sets fields and data type we intend to use for them Field Name. Data Typecomplaintidtextdatereceiveddateproducttextsubproducttextissuetextsubissuetextconsumercomplaintnarrativetextcompanypublicresponsetextcompanytextstatetextzipcodetexttagstextconsumerconsentprovidedtextsubmittedviatextdatesentdatecompanyresponsetoconsumertexttimelyresponsetextconsumerdisputedtext. You may be wondering why some of the numeric fields like zipcode and complaintid are stored as text. The general rule of thumb is to always store numeric characters as text unless you are planning on doing some type of mathematical calculations on the values themselves. As an example here is an example of a field containing numbers that youd want to store as a numeric type, and one that you wouldnt Store as numeric type An age field stores peoples ages and they want to do things like find the average of a person living in a certain zip code. Store as text An ID field of some sort that you cannot do any mathematical functions on. Generally speaking, you cant add, multiply, or perform any other type of arithmetic on a zip code that would make any sense. Downloading Installing Postgre. SQLThe first thing youll need to do is setup Postgre. SQL if you dont yet have it set up. Below are download links for the major operating systems. Create New User, Database, and Tables. We need to create two new tables to store the data in the files that we downloaded, earlier. You can achieve this several different ways, but were going to use the psql shell throughout this tutorial. To open the psql shell, this can be achieved by opening a a command prompt Windows or terminal Mac window, and typing psql and hitting enter. This will launch the psql shell. If this is your first time using psql shell, your user will likely not have necessary permissions to launch the utility. First, you will need to use an account with administrator privileges, and then use psql U postgres to login with the postgres user which was created automatically during the install 3. Type help for help. The postgres that you see is the psql prompt, and postgres will be replaced with whichever database you are connected to. Were going to create a new user for our database. For this tutorial well call our user oracle, but you can use anything, and its convenient to use the same username you use for your operating system, as you then dont have to worry about passwords or specifying a user moving forward. To create a new user, we use the following syntax CREATEROLEname. WITHoptionsgohere Click here for the documentation regarding the CREATE ROLE statement. Here youll find all of the available options and relative DESCriptions. Were going to give this new user the following permissions. SUPERUSER The user will be a superuser. CREATEDB The user will be allowed to create databases. CREATEROLE The user will be allowed to create new roles. LOGIN The user will be able to login. INHERIT The user will inherit all privelages of roles its a member of. Lets create the new user, oracle, with the password welcome. CREATEROLEoraclepasswordwelcome. SUPERUSERCREATEDBCREATEROLEINHERITLOGIN Our new user should now be created. Lets check to make sure our new user has sufficient privileges. Enter the command du and hit enter. Your user should have the following permissions. List of roles. Role name Attributes Member of. Superuser. Create role. Create DB. Postgres Superuser. Create role. Create DB. This will allow you to connect using the oracle user from now on. For now, we can switch over to the oracle user using the command. If we had quit the psql shell using q we can connect when we launch the psql shell 3. U oracle postgres. Type help for help. The U flag allows us to specify the user, and the postgres specifies the postgres account database if we dont specify a database here, well get an error. Now that were logged in as the oracle user, were going to create a new database. To create a new database, we use the following syntax CREATEDATABASEdatabasename The CREATE DATABASE statement has a lot more options that we dont need right now if you like you can read about them in the documentation. Now, lets create the new database, consumercomplaints.