MYSQL Query How to get first 10 char from $_GET from column customername from mytable.
SELECT * FROM mytable WHERE 'customername'=".mysql_real_escape_string($_GET['name'])"
Which operator to use ? TOP selects rows
I want to get first 10 characters of all records in column customername.
Related
I have tried to select something with SQL, and I've a problem with it.
What I want:
SQL SELECT * FROM table WHERE ? = '5';
Select everything which = 5, BUT not specify from which column.
Example:
From this ""database"", you should receive the 1st and the last row.
Is that possible?
You have to list the columns but you can use in. The where clause looks like:
where 5 in (price, height)
Note: This assumes that the columns have the same type. You could get type conversion errors if they are not.
Also, given the names of the column and the data, I assume that the columns are stored as numbers. Hence, I dropped the single quotes around 5. If they are really strings, then use the single quotes.
you need to add a condition to your query with or keyword so if any of them match the row will be shown as a result
SELECT * FROM tablename WHERE price =5 or height= 5
better you list your columns by name instead of using * after SELECT
At the moment I am running a simple select query i.e.
SELECT * FROM `form_expense`
One of the columns in this case titled 'value' returns the following text list_expense_category. I would like to then look up all the values in the table list_expense_category and replace the value with all the results separated by a comma.
I know I am able to do this with an inner join if the value always references the same table but how would I go about this if the value could reference different tables. i.e.
Row 1 - value = list_expense_category
Row 2 - value = list_expense_projects
Row 3 - value = list_expense_currency
I have an events table with a field called breaks. This is populated with data in a comma separated format, i.e. 1,2,3 or 1 or 1,4,5 - the same format that MySQL's IN command uses.
I'd then like to run a query - on the slots table - to return all rows apart from those specified in events.breaks.
The query, theoretically, should be something like this:
SELECT
`slots`.`id` AS id,
RIGHT(`slots`.`time`, 8) AS `time`
FROM
`slots`, `event`
WHERE
`slots`.`id` NOT IN (`event`.`breaks`)
But that doesn't appear to work - if event.breaks is 4,5,7, the only row from the slots table that doesn't return is 4!
SQLFiddle here: http://sqlfiddle.com/#!2/913fe/1/0
You're passing a single field to the NOT IN () clause, not a subexpression. Think of it like this
(1, 2, 3)
is roughly the same as
SELECT 1
UNION
SELECT 2
UNION
SELECT 3;
as a subexpression. What you're doing instead is
('4,5,7')
which is roughly equivalent to
SELECT '4,5,7';
which in turn MySQL probably converted to a number for the comparison and the result is
NOT IN (4)
What you're actually trying to do isn't really supposed to be done like that. It'd be better if you added an AxB relation table so you can select several rows with the IDs you don't want.
Give this a try:
SELECT slots.id AS id, RIGHT(slots.time, 8) time
FROM slots, event
WHERE FIND_IN_SET(slots.id, event.breaks) = 0
This is how the FIND_IN_SET(str,strlist) function works:
Returns a value in the range of 1 to N if the string str is in the string list strlist consisting of N substrings. A string list is a string composed of substrings separated by “,” characters. [...] Returns 0 if str is not in strlist or if strlist is the empty string.
Also note that IN (val1, val2, val3) is NOT the same as IN (val4) where val4 is a commma-separated string. The IN clause will compare by equality.
you may need a subselect to return the split string
... NOT IN (SELECT your_split_fnc(`event`.`breaks`) FROM `events`)
See answers here for a way to split strings in MySQL Can Mysql Split a column?
instr() MySQL function could be of help also
... INSTR(event.breaks,id) = 0
http://dev.mysql.com/doc/refman/5.0/en/string-functions.html#function_instr
I have a mysql query where I give value of a column in list " WHERE IN" and I want to order my result same order I give in list. Is it possible?
My SQL query is like
SELECT *
FROM <TABLE NAME>
WHERE id IN (2,12,56,5,9)
I want the result to be in same order as I gave inside my list i.e. 2,12,56,5,9
SELECT *
FROM table_name
WHERE name IN (2,12,56,5,9)
ORDER BY FIELD(id,2,12,56,5,9)
Returns the index (position) of id in the 2,12,56,5,9 list. Returns 0 if str is not found.
If all arguments to FIELD() are strings, all arguments are compared as strings. If all arguments are numbers, they are compared as numbers. Otherwise, the arguments are compared as double.
FIELD()
Yes, it's possible.
SELECT ...
ORDER BY
CASE
WHEN id = 2 THEN 1
WHEN id = 12 THEN 2
WHEN id = 56 THEN 3
...
END
My query is like this
select 5 from mytable_name;
Then the output is like column name 5 and the value is 5 printing as many max number of rows exists in that table.
Can anybody tell the reason why this query is working like this?
Can anybody tell the reason why this query is working like this?
You are selecting a string literal value '5' for each row in your table:
select 5 from mytable_name;
And this works fine. Because in the SELECT statement you can select:
Column reference,
Literal value like in your case.
Function.
value expression.
Select expression.
As defined by the standard SQL1:
Update:
However, If you have a column with a name is a number like in your case, you have to escape it in order to select the values in it like so:
SELECT `143` FROM Table1;
This will select all the rows in the column 143.
But, this:
SELECT 143 FROM Table1;
Will select the string literal 143 for each row found in the table.
Note that: If possible, try not to name these columns this way, it is recommended and a best practice, not to do this.
SQL Fiddle Demo
Update 2:
Note that, if you select 143 or '143', or even "143" this will select the literal value 143 not the column date. The following are the same:
SELECT 143 FROM Table1;
SELECT '143' FROM Table1;
SELECT "143" FROM Table1;
All these SELECTs won't select the data in the column, They will select the literal value 143 not the column data. See this demo:
Demo
You have to escape the column name with the two:
``
Like this:
SELECT `143` FROM table1;
Not:
SELECT '143' FROM table1'
Like what I did here:
The right Demo
1Image From: SQL Queries for Mere Mortals
from mytable
will select all rows from your table if there is no where condition that shrinks that result. and
select 5
will select the constant number 5 for every record. If you use a column name in the select part then that value will be selected for every record.
The DB engine will name the result 5 because it automatically generates a column name and 5 is the logical name for that.
You want 'SELECT * FROM mytable_name LIMIT 0,5' perhaps?
Since you don't have anything in your where clause, it is selecting all the rows from your table. The fact that you don't select any of the columns is irrelevant - you'll still get a result for each row in the table.
With the command select 5 ... you are viewing a fixed value. Same thing you run the following command: select "test", you will be displaying a fixed string.
Using ... from mytable_name you're looking for all record of this table.
With this we can conclude that for each record in the table mytable_name shows you the fixed value "5".