How can I select a row specific by string values
SELECT * FROM my_table WHERE name=
-- then some function to test what string it starts with
Its a bit hard to explain so i will explain an example with JavaScript
if(mystring.indexOf('targetstring') != -1){
// if that variable contains this string
}
if(mystring.indexOf('targetstring') == 0){
// if that variable starts with this string
}
So all in all, I want to select rows, when their name(a string column) starts with or contains a specific string.
You can use LIKE and the wildcard %:
SELECT * FROM my_table WHERE name LIKE 'john%'; /* name starts with john*/
SELECT * FROM my_table WHERE name LIKE '%john%'; /* name contains john*/
SELECT * FROM my_table WHERE name like "%string%"
Related
I want to CONCAT value in ID column in string variable and use the variable with IN in SQL as under:
SET #ActID = CONCAT(CAST(5 AS CHAR),',',CAST(15 AS CHAR));
SELECT * FROM `accounts` WHERE `ID` IN (#ActID);
It returns record having ID = 5 and ignore record having ID = 15.
#ActID is a comma separated list string literal and not a list of values.
So the list inside the parentheses of the IN operator contains only 1 value: '5,15'
when you compare 5 to '5,15' the result is TRUE
when you compare 15 to '5,15' the result is FALSE
because '5,15' is converted to the integer value 5 according to the rules described here.
What you want is the function FIND_IN_SET():
SET #ActID = CONCAT(CAST(5 AS CHAR),',',CAST(15 AS CHAR));
SELECT * FROM `accounts` WHERE FIND_IN_SET(`ID`,#ActID) > 0;
Change to ...= 0 for the equivalent of NOT IN.
See a simplified demo.
Note: SET #ActID = CONCAT(5,',',15); works fine.
How can I select from database by given string and mysql to return the row on same string with diacritics?
select * from myTable where nume = "Stefan"
and the row from database that should be returned:
id = 1
name = "Ștefan"
You can search like:
SELECT * from myTable
where
CONVERT(nume USING utf8) LIKE '%Stefan%'
But this is a bit unclear, as MySql already know how to search for strings with diactritics.
I have a mysql query in java like
public static BusObjectIterator<con.PROJECT_EMP> GetEmpObjectsforOrgandMultipleCategory(String ORG, String CATEGORY)
{
String query=select * from PROJECT_EMP where org = :ORG and category=:CATEGORY;
.....
return ...
}
Here the param ORG will have single value like xyz and CATEGORY String may have multiple values like Cat1,Cat2 etc..,
So dynamically i would like to frame query using REGEX to replace the comma separated string values like
select * from PROJECT_EMP where org = 'xyz' and category in ('Cat1','Cat2');
Thanks.
You can use FIND_IN_SET() function instead of RegEx
Try this:
SELECT * FROM PROJECT_EMP WHERE org = :ORG AND FIND_IN_SET(category,:CATEGORY);
I have a function which takes an argument that is used in where clause
function(string x)-->Now this will create a sql query which gives
select colname from tablename where columnname=x;
Now I want this function to give all rows i.e. query equivalent to
select colname from tablename;
when I pass x="All".
I want to create a generic query that when I pass "All" then it should return me all the rows else filter my result.
Just leave the where condition out.
If you really want it that complicated use
where columnname LIKE '%'
which will only filter nulls.
select colname from tablename
where columnname=(case when #x ="All" then columnname
else #x end)
Try this
select colname from tablename where 1=1
hope the above will work
where 1=1 worked for me, Although where clause was being used all records were selected.
You can also try
[any_column_name]=[column_name_in_LHL]
(LHL=left hand side.)
refer my answer for more details
I had the same issue some time ago and this solution worked for me
select colname from tablename where columnname=x or x = 'ALL'
SELECT * FROM table_name WHERE 1;
SELECT * FROM table_name WHERE 2;
SELECT * FROM table_name WHERE 1 = 1;
SELECT * FROM table_name WHERE true;
Any of the above query will return all records from table.
In Node.js where I had to pass conditions as parameter I used it like this.
const queryoptions = req.query.id!=null?{id : req.query.id } : true;
let query = 'SELECT * FROM table_name WHERE ?';
db.query(query,queryoptions,(err,result)=>{
res.send(result);
}
It's unclear what language you're using for your function, but you have to somehow parse the 'All' prior to getting to sql:
public void query(String param) {
String value = "":
switch (param) {
case 'All':
value = "*";
break;
default:
value = param;
}
String sql = "select colname from tablename where colname="+value;
//make the query
}
If you have to allow 'ALL' to be passed through as the parameter value to your function, then you will need to put some manipulation code in your function to construct your SELECT statement accordingly. I.e. You can detect if the parameter has 'ALL' in it and then omit the WHERE clause from your SQL statement. If a value other than 'ALL' comes through, then you can include the WHERE clause along with the relevant filter value from the parameter.
An example of a piece of code to do this would be;
IF x = 'ALL'
THEN
SELECT COLNAME FROM TABLENAME;
ELSE
SELECT COLNAME FROM TABLENAME WHERE COLUMNNAME = X;
END IF;
Give a conditional check in your code(assuming Java) to append the WHERE clause only when x != 'All'
mySqlQuery = "SELECT colname FROM tablename" +
(x.equals("All") ? "" : "WHERE columnname = "+x);
I have procedure with a single string parameter to retrieve records from my table test which has two fields id(int) and Name(varchar).
the query in the procedure is shown below
Select * from test where id in (strParam);
and value in the parameter will be
strParam="1,2";
but the result will be wrong because query will be as shown below
Select * from test where id in ('1,2');
but i need the query to be like shown below
Select * from test where id in (1,2);
please help me with a solution
the programming language is C#
thanks,
suraj
Usually you construct the SQL correctly in your programming language:
Select * from test where id in ('1,2');
should come from your application code, where it's easier to change strParam="1,2"; to strParam="'1','2'":
Split (explode) the string into an array
escape each element in the array (using the correct MySQL-ESCAPE function)
Join (implode) the array back into a string,
If you really can't change the application code, maybe some SQL tricks could work. Try:
SELECT * FROM test where FIND_IN_SET(ID,strParam) > 0
Not sure if this is the most efficient way:
Explode the value strParam to an array and then build up the string you need in the query:
<?php
$arrayParam = explode(',', $strParam);
$strParamQuery = '(';
foreach ($arrayParam as $Param) {
if ($strParamQuery != '(') { $strParamQuery = $strParamQuery.','; //Add a comma to all but the first occurence
$strParamQuery = $strParamQuery.$param;
}
$strParamQuery = $strParamQuery.')';
$query = 'Select * from test where id in '.$strParamQuery.';';
?>