![]() Here’s what the final query looks like: SELECT customer_id, CONCAT(first_name, “ “, last_name) AS full_name, LENGTH(CONCAT(first_name, last_name)) AS name_length FROM customer Go ahead and rename the new column as Name Length and close the query: ![]() We want to count every character in the first and last names, not including space we added earlier, so we’re going to rewrite our CONCAT function for LENGTH. SELECT customer_id, CONCAT(first_name, “ “, last_name) AS full_nameĪnd then add LENGTH. So first set the columns you want to view with SELECT : Here is a visual break down of what this query does: But if CONCAT is used for numerical calculations, you won’t be able to reproduce this query. In the previous example, the CONCAT function's result was a string corresponding to the customer’s name ( full_name), so we can use it with no problems. You can use strings or string columns directly within the LENGTH function, but for this example, we will use CONCAT. This function accepts string data as an input value and calculates how many characters it has and output numbers (calculates based on bytes). Sometimes it is necessary to calculate the length of a string. Let’s count the length of the customer’s full name (characters in the first and last name). I am ", first_name, “ “, last_name) AS full_name FROM customer □ Fun Tip! You can also add in some extra text with CONCAT like this: SELECT customer_id, CONCAT("Hello. SELECT customer_id, CONCAT(first_name, “ ”, last_name) AS full_name FROM customer Your full and final query will look like this: Make sure you separate all three with commas :Īnd finally, close it with the name of the table and a semicolon. To add a space between the two, we need to explicitly put one there and highlight it with double quotations (“ ”). We also want to see the full name, so let’s use CONCAT to connect the first and last names. Start with specifying which column you want to see: customer ID And to combine the two in MySQL, you need CONCAT. You may need the full name together in more complicated queries, so it’s good to know how to connect the two into one line. The table shows the customer's first and last names stored in different columns. ![]() Combine customer first and last name columns to make a new name column (CONCAT) Let’s print out only three characters of the customer’s name (SUBSTR) SELECT customer_id, CONCAT(first_name, “ “, last_name) AS full_name, SUBSTR(CONCAT(first_name, “ “, last_name), 1, 3) AS short_name FROM customer Let’s count the length of the customer’s full name (LENGTH) SELECT customer_id, CONCAT(first_name, “ “, last_name) AS full_name, LENGTH(CONCAT(first_name, last_name)) AS length_name FROM customer Combine customer first and last name columns to make a new name column (CONCAT) SELECT customer_id, CONCAT(first_name, “ “, last_name) AS full_name FROM customer We will cover string data based on MySQL. There are many functions for strings, and sometimes different databases such as Oracle, SQL Server, and MySQL have different methods. ĮDITED TO CLARIFY: I know that group_concat supports an ORDER BY clause but I don't want the column that I sort by (posTime) to be returned in the results.In this tutorial, we will learn about the functions you can use to manipulate string data easily. How can I sort the position reports for each id by increasing posTime before concat'ing them together ? In theory it's just a case of adding ORDER BY posTime ASC but I'm not sure how or where to add this to my query as all previous attempts have failed. However I'm not 100% confident that the position reports are in the correct time order. ObjectId | X1, Y1, heading1, speed1, X2, Y2, heading2, speed2. My table structure is: CREATE TABLE tracks ( ![]() This keeps the table relatively small for the number of objects that I'm tracking.Įach row contains data on a single object at a moment in time and whilst these should go into the database in chronological I want to ensure that I pull the data out in chronological order before concat'ing them together so that I can plot out the data. Rather than store their location every few seconds I simply store their location, direction, speed and time whenever it changes. I have a system that tracks several thousand objects in realtime and stores their locations in a database table. ![]()
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