I have a column with type string, and we saved all sizes and prices in this field it is separated by pipeline and semicolon sign as shown below
10;100|11;111|12;112|13;130|14;130|15;105
I want to get the minimum price in this field (price;size where 10 is size and 1502 is price).
I used this query but it returns only one of them and not the minimum
select SUBSTRING_INDEX((textColumn), '|', 1) as sizeAndprice from myTable;
If the structure can be changed, I would suggest in doing so.
However, if it cannot be changed whatever the reason, I would fetch the entire row as it is and use the explode() function:
/* fetch the whole column as string in a variable ($myWholeText for this example) */
$mySplitColumns = explode ("|", $myWholeText );
You will then have all the split values (both price and size) in a separate index of array $mySplitColumns, and you will be able to sort them out as you like.
For more reference about the explode function, check this link
Related
I have a MySQL table setup where one column's values are a string of comma-separated True/False values (1s or 0s). For example, in the column, one field's value may be "0,1,0,0,0,0,1,1,0" and another may be "1,0,0,1,1,1,0,0,0" (note: these are NOT 9 separate columns, but a string in one column). I need to QUERY the MySQL table for elements that are "true"(1) for the "nth element" of that column's value/string.
So, if I was looking for rows, with a specific column, where the 3rd element of the column's value was 1, it would produce a list of results. So, in this case, I would only be searching for "1" in the fth place (12345 = X,X,X...) of the string (X,X,1,X,X,X,X,X,X,X). How can I query this?
This is a crude example of what I am trying to do ...
"SELECT tfcolumn FROM mytable WHERE substr({tfcolumn}, 0, 5)=1"
{tfcolumn} represents the column value
5 represents the 5th position of the string
=1 represents what I need that position to equal to.
Please help. Thanks
You can't. Once you put a serialized data type into a column in SQL (like comma separated lists, or JSON objects) you are preventing yourself from performing any query on the data in those columns. You have to pull the data in a different way and then use a program like python, VB, etc to get the comma separated values you are looking for.
Unless you want to deal with trying to make this mess of a query work...
I would recommend changing your table structure before it's too late. Although it is possible, it is not optimized in a format that a DBMS recognizes. Because of that the DBMS will spend a significant amount of time going through every record to parse the csv values which is something that it was not meant to be doing. Doing the query in SQL will take as much time (if not more time) than just pulling all the records and searching with a tool that can do it properly.
If the column contains values exactly like the ones you posted, then the Nth element is at the 2 * N - 1 position in the comma separated list.
So do this:
SELECT tfcolumn
FROM tablename
WHERE substr(tfcolumn, 2 * 5 - 1, 1) = '1'
Replace 5 with the index that you search for.
See the demo.
Or remove all commas and get the Nth char:
SELECT tfcolumn
FROM tablename
WHERE substr(replace(tfcolumn, ',', ''), 5, 1) = '1'
See the demo.
Try this
if substring_index(substring_index('0,1,0,0,0,0,1,1,0',',',3),',',-1)='1'
The first argument can be your column name. The second argument (',') tells the function that the string is comma-separated. The third argument takes the first 3 elements of the string. So, the output of inner substring_index is '0,1,0'.
The outer substring_index has -1 as the last argment. So, it starts counting in reverse direction & takes only 1 element starting from right.
For example, if the value in a particular row is '2,682,7003,14,185', then the value of substring_index(substring_index('2,682,7003,14,185',',',3),',',-1) is '7003'.
I'm querying an SQL database that I have read only access to (Cannot edit tables/create columns etc)
My table contains a column with JSON strings that have (Actual strings are much larger, this is just an example) the following syntax
{"value":"442","country":"usa"}
I would like to add the values contained in the JSON string from each row together and output it as readable, if this is possible?
The values are in the same point of the JSON, as shown above. The values vary in length also, most are 3/4 characters long.
Try the following (for MySQL v5.7+):
select sum(json_extract(jsonString, '$.value')) from mytable;
An example of this is here.
I need to find intersect value from two comma separated string in stored procedure.
String 1: 40,31,42,23,45 => System generated numbers
String 2: 30,23,24,31,25,32 => User selected numbers
I want to check that, do any of my numbers are present in system generated numbers.
Above value should return 23,31.
I have solution that, i will loop through system generated numbers and will check one by one with my numbers using FIND_IN_SET, if present i will CONCATE that and will get required output.
But is there any shorter and optimized way to do this?
I have downloaded a MySQL table as CSV, which has over thousand entries of the following type:
id,gender,garment-color
1,male,white
2,"male,female",black
3,female,"red,pink"
Now, when I am trying to create a chart out of this data, it is taking "male" as one value, and "male,female" as a separate value.
So, for the above example, rather than counting 2 "male", and 3 "female", the chart is showing 3 separate categories ("male", "female", "male,female"), with one count each.
I want the output as follows, for chart to have the correct count:
id,gender,garment-color
1,male,white
2,male,black
2,female,black
3,female,red
3,female,pink
The only way I know is to copy the row in MS Excel and adjust the values manually, which is too tedious for 1000+ entries. Is there a better way?
From MySQL command line or whatever tool you are using to send queries to MySQL:
select * from the_table
into outfile '/tmp/out.txt' fields terminated by ',' enclosed by '"'
Then download /tmp/out.txt' from the server and it should be good to go assuming your data is good. If it is not, you might need to massage it with some SQL function use in theselect`.
The csv likely came from a poorly designed/normalized database that had both those values in the same row. You could try using selects and updates, along some built in string functions, on such rows to spawn additional rows containing the additional values and update their original rows to remove those values; but you will have to repeat until all commas are removed (if there is more than one in some field), and will have to determine if a row containing multiple fields with such comma-separated lists need multiplied out (i.e. should 2 gender and 4 color mean 8 rows total).
More likely, you'll probably want to create additional tables for X_garmentcolors, and X_genders; where X is whatever the original table is supposed to be describing. These tables would have an X_id field referencing the original row and a [garmentcolor|gender] value field holding one of the values in the original rows lists. Ideally, they should actually reference [gender|garmentcolor] lookup tables instead of holding actual values; but you'd have to do the grunt work of picking out all the unique colors and genders from your data first. Once that is done, you can do something like:
INSERT INTO X_[garmentcolor|gender] (X_id, Y_id)
SELECT X.X_id, Y.Y_id
FROM originalTable AS X
INNER JOIN valueTable AS Y
ON X.Y_valuelist LIKE CONCAT('%,' Y.value) -- Value at end of list
OR X.Y_valuelist LIKE CONCAT('%,' Y.value, ',%') -- Value in middle of list
OR X.Y_valuelist LIKE CONCAT(Y.value, ',%') -- Value at start of list
OR X.Y_valuelist = Y.value -- Value is entire list
;
I have a table with about 50,000 records. One of the fields is a "imploaded" field consisting of variable number of parameters from 1 to 800. I need to replace all parameters to 0.
Example:
1 parameter 3.45 should become 0.00
2 parameters 2.27^11.03 should become 0.00^0.00
3 parameters 809.11^0.12^3334.25 should become 0.00^0.00^0.00
and so on.
Really I need to replace anything between ^ with 0.00 ( for 1 parameter it should be just 0.00 without ^).
Or I need somehow count number of ^, generate string like 0.00^0.00^0.00 ... and replace it. The only tool available is MySqlWorkbench.
I would appreciate any help.
There is no regex replace capability built in to MySQL.
You can, however, accomplish your purpose by doing what you suggested -- counting the number of ^ and crafting a string of replacement values, with this:
TRIM(TRAILING '^' FROM REPEAT('0.00^',(LENGTH(column) - LENGTH(REPLACE(column,'^','')) + 1)));
From inside to outside, we calculate the number of values by counting the number of delimiters, and adding 1 to that count. We count the delimiters by comparing the length of the original string, against the length of the same string with the delimiters stripped out using REPLACE(...,'^','') to replace every ^ with nothing.
The REPEAT() function builds a string by repeating a string expression n number of times.
This results in a spurious ^ at the end of the string, which we remove easily enough with TRIM(TRAILING '^' FROM ...).
SELECT t1.*, ... the expression above ... FROM table_name t1, from your table to verify the results of this logic (replacing column with the actual name of the column), then you can UPDATE table SET column = ... to modify the values. once you are confident in the logic.
Note, of course, that this is indicative of a problematic database design. Each column should contain a single atomic value, not a "list" of values, as this question seems to suggest.