Previously we looked at finding data in a SQL database and The UPDATE statement is used to update records in a table. You can also use the UPDATE statement to update existing records in a table. When using the SQL UPDATE statement, we’ll also use the WHERE clause, as we used previously to constrain output of a SELECT statement. The WHERE locates the record(s) to be updated with syntax as follows: UPDATE table SET column=value,column=value,... WHERE column=value; The WHERE clause indicates the record(s) to update. I’ve forgotten to put it in in the past and updated every record of a database. That’s bad (unless you mean to do it). So…
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Add New Records To MySQL Databases With The INSERT Statement
Sometimes you need to write a record into a table in a SQL database. The INSERT INTO statement creates new records in a table and can work in one of two ways. The first form does not specify the column names where the data will be inserted, only their values. When doing so, each value needs to be inserted in the columned order they appear, here the table being the name of the table you’re adding a record into and each value would be replaced with the contents of your value (don’t insert the string ‘value’ into each!): INSERT INTO table VALUES (value,value,value,...); If you don’t have every value to…
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Compound Searches With SQL Using AND && OR
Previously, we looked at the SQL SELECT and WHERE options to obtain output and then constrain what would be displayed in a query. The AND & OR operators are used to add additional logic so you can filter records based on more than one condition. Which is to say to search based on the contents of multiple columns within a single table. AND is used to show information if two different conditions are true and OR is used to show information if either condition is true. Below is a selection from the “Customers” table that showed in our first article an we will use it to run some SQL sorting…
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Constrain SQL Queries Using WHERE and LIKE
Previously, we covered the SQL SELECT Statement, to pull data from a SQL database. Here, we’ll constrain our search for items that match a given string, or pattern using the WHERE clause to filter search results, rather than getting all of the records and parsing the output. The WHERE clause extracts records that fulfill a specified string and follows the general syntax as follows, replacing the word column with the name of the column in one of your tables and the word table with the name of a table that you’d like to search within: SQL WHERE Syntax SELECT column,column FROM table WHERE column operator value; Below is a selection…
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Us the ORDER BY Keyword With Your SQL SELECT Statements
The ORDER BY keyword in a SQL SELECT statement is used to sort a given result-set based on the contents of one or more columns of data. By default, results are in ascending order, but you can use either ASC or DESC to indicate that you’d like results sorted in ascending or descending order, respectively. Below is a selection from the “Customers” table that we will use to run some SQL sorting statements using the ORDER BY keyword: ID Site Contact Address City Zip Country 1 Krypted Charles Edge my house Minneapolis 55418 US 2 Apple Tim Cook spaceship Cupertino 95014 US 3 Microsoft Satya Nadella campus Redmond 98053 US…
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The SQL SELECT Statement
Most tasks you will execute against a database are done with SQL statements. Think of statements as a query, an insert, a change, or a delete operating. For example, to see all of your data, you would select all of the records from a database using the SELECT statement. Then we’ll ask for all, or *, and tell the command to show us where the data is coming from, which is the Customers table. Finally, we’ll be nice and tidy and put a semi-colon at the end; although if you forget, you can always do so after you hit return: SELECT * FROM Customers; As can be seen above, the…
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Your First SQL Statement
Databases and Tables A SQL database is an organized collection of data. Or at least that’s what they taught me in college. In real life, it’s only as organized as the people putting data into the database. Databases contain schemas, tables, stored procedures, reports, views and other objects. Most databases will contain multiple tables. Tables contain rows that have data in them. I like to think of a database kinda’ like an Excel spreadsheet. Each tab on a spreadsheet is similar to a table; each row is similar to a row in a database and each column in the spreadsheet is somewhat similar to a column, or attribute. The headers…
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Scripting Azure On A Mac
Microsoft Azure is Microsoft’s cloud services. Azure can host virtual machines and act as a location to store files. However, Azure can do much more as well, providing an Active Directory instance, provide SQL database access, work with hosted Visual Studio, host web sites or provide BizTalk services. All of these can be managed at https://manage.windowsazure.com. You can also manage Windows Azure from the command line on Linux, Windows or Mac. To download command line tools, visit http://www.windowsazure.com/en-us/downloads/#cmd-line-tools. Once downloaded, run the package installer. When the package is finished installing, visit /usr/local/bin where you’ll find the azure binary. Once installed, you’ll need to configure your account from the windowsazure.com site to…
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Fix Table Corruption In MySQL
Corruption happens. Sometimes, it’s little things that cause problems. With MySQL, the mysql command line tool has long held the answer for easy corruption issues. There are a number of tools to repair corruption, but the place to start is the REPAIR command within that trusty mysql command line tool. To start, let’s try a backup. In this case, I’m going to use a tool those of us who deal with Media Assets frequently tinker with, CatDV. I’m going to backup the databases with a simple mysqldump command, defining the user and then piping the data out to some backup file, which in this case is catdvbak on the desktop:…
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Working with Postgres from the Command Line in Lion Server
Mac OS X Server 10.7, Lion Server, comes with a few substantial back-end changes. One of these is the move from SQLite3 to PostgreSQL for many of the back-end databases, including Wiki and Podcast Producer (collab), Webmail (roundcubemail), iCal Server and Address Book Server (caldav) and as the back-end to the newest service in Lion Server, Profile Manager (device_management). As such, it’s now important to be able to use PostgreSQL the way we once used SQLite3, when trying to augment the data that these databases contains, as there currently aren’t a lot of options for editing this data (aside from manually of course). Postgres has a number of commands that…