I want to know which of the conditions in ORs matched, making only one request
The SQL below is wrong. What is a right way to do it?
select 'MATCHED',
case
WHEN flield1='xxx' THEN result=concat(result, ' field1 matched ' )
WHEN flield2='yyy' THEN result=concat(result, ' field2 matched ' )
WHEN flield3='zzz' THEN result=concat(result, ' field3 matched ' )
end as result
from table
where flield1='xxx' OR field2='yyyy' OR field3='zzzz';
I want to get result like this:
result
MATCHED
field1 matched field3 matched
MATCHED
field2 matched
MATCHED
field1 matched field2 matched field3 matched
You need a separate case expression for each condition column:
select 'MATCHED',
concat(
case when flield1 = 'xxx' then 'field1 matched ' else '' end,
case when flield2 = 'yyyy' then 'field2 matched ' else '' end,
case when flield3 = 'zzzz' then 'field3 matched' else '' end) as result
from table
where flield1 = 'xxx' OR field2 = 'yyyy' OR field3 = 'zzzz';
Related
How to use the And, OR condition in the same MySQL where query.
SELECT * FROM Table_name
WHERE filed_name = 0 AND (field1 != '' AND field2 ='')
OR (field1 = '' AND field2 != '') AND filed3 = 1;
I want to more than 2 fileds in brackets.
You can include as many conditions as you need within parentheses, but you do need to be careful with OR and you may find it necessary to combine multiple sets of conditions with parentheses. When this happens consistent formatting and use of indents can help you maintain the required logic.
SELECT *
FROM Table_name
WHERE (field_name = 0
AND (field1 != '' AND field2 ='')
)
OR (field3 = 1
AND (field1 = '' AND field2 != '')
)
;
Do note that the query above is a guess; I have assumed you need 2 sets of conditions.
SQL refer to columns (not at fields)
anyway you can use all the columns you need in each where condition
SELECT *
FROM Table_name
WHERE col0 = 0
AND col1 != ''
AND col2 =''
OR (col1 = '' AND col2 != '' AND col3 ='YOUR_VALUE')
AND col3 = 1
OR (col4 = 'your_value4' AND col5> 100 );
the parentheses are needed for change the priority in evalaution of the condition ...
I'm working in a query using JOOQ and I'm trying to output a column as a
concatenation (space separated) of other fields extracted in the same query.
Getting into detail, with the next code I try to create a select statement with a column called fullAdress by grouping all the address lines contained in the address table. So, for each field, if it's not null or empty it will be concatenated to the result (actually no space is being added).
#Override
protected List<Field<?>> selectCustomFields() {
List<Field<?>> customSelect = new ArrayList<Field<?>>();
// Fields to use in the concatenation
Field<?> field1 = field("addr.AddressLine1"), field2 = field("addr.AddressLine2"),field3 = field("addr.AddressLine3"),
field4 = field("addr.AddressLine4"), field5 = field("addr.PostalCode"), field6 = field("addr.City"),
field7 = field("addr.State"), field8 = field("addr.County"), field9 = field("addr.Country");
// Create non null/empty conditions
Condition condLine1 = field1.isNotNull().and(field1.length().ne(0));
Condition condLine2 = field2.isNotNull().and(field2.length().ne(0));
Condition condLine3 = field3.isNotNull().and(field3.length().ne(0));
Condition condLine4 = field4.isNotNull().and(field4.length().ne(0));
Condition condLine5 = field5.isNotNull().and(field5.length().ne(0));
Condition condLine6 = field6.isNotNull().and(field6.length().ne(0));
Condition condLine7 = field7.isNotNull().and(field7.length().ne(0));
Condition condLine8 = field8.isNotNull().and(field8.length().ne(0));
Condition condLine9 = field9.isNotNull().and(field9.length().ne(0));
// Concat address lines when meets condition
customSelect.add(concat(DSL.when(condLine1, field1),
DSL.when(condLine2, field2),
DSL.when(condLine3, field3),
DSL.when(condLine4, field4),
DSL.when(condLine5, field5),
DSL.when(condLine6, field6),
DSL.when(condLine7, field7),
DSL.when(condLine8, field8),
DSL.when(condLine9, field9))
.as("fullAddress"));
return customSelect;
}
JOOQ will generate the next from the previous select statement, which is giving a null value and not concatenating the fields correctly.
select
concat(
cast(case when (
addr.AddressLine1 is not null
and char_length(cast(addr.AddressLine1 as char)) <> 0
) then addr.AddressLine1 end as char),
cast(case when (
addr.AddressLine2 is not null
and char_length(cast(addr.AddressLine2 as char)) <> 0
) then addr.AddressLine2 end as char),
cast(case when (
addr.AddressLine3 is not null
and char_length(cast(addr.AddressLine3 as char)) <> 0
) then addr.AddressLine3 end as char),
cast(case when (
addr.AddressLine4 is not null
and char_length(cast(addr.AddressLine4 as char)) <> 0
) then addr.AddressLine4 end as char),
cast(case when (
addr.PostalCode is not null
and char_length(cast(addr.PostalCode as char)) <> 0
) then addr.PostalCode end as char),
cast(case when (
addr.City is not null
and char_length(cast(addr.City as char)) <> 0
) then addr.City end as char),
cast(case when (
addr.State is not null
and char_length(cast(addr.State as char)) <> 0
) then addr.State end as char),
cast(case when (
addr.County is not null
and char_length(cast(addr.County as char)) <> 0
) then addr.County end as char),
cast(case when (
addr.Country is not null
and char_length(cast(addr.Country as char)) <> 0
) then addr.Country end as char)) as `fullAddress`
from Address as `addr`
....
My questions are,
how should I create my select statement correctly?
how can I best add the space separator?
is there any better alternative to JOOQ ( when = case ) condition clause?
how should I create my select statement correctly?
You forgot the CASE .. ELSE part, or otherwise() in jOOQ:
// Concat address lines when meets condition
customSelect.add(concat(DSL.when(condLine1, field1).otherwise(""),
DSL.when(condLine2, field2).otherwise(""),
DSL.when(condLine3, field3).otherwise(""),
DSL.when(condLine4, field4).otherwise(""),
DSL.when(condLine5, field5).otherwise(""),
DSL.when(condLine6, field6).otherwise(""),
DSL.when(condLine7, field7).otherwise(""),
DSL.when(condLine8, field8).otherwise(""),
DSL.when(condLine9, field9).otherwise(""))
.as("fullAddress"));
how can I best add the space separator?
If you want an additional space separator between your address parts, you could write:
// Concat address lines when meets condition
customSelect.add(concat(DSL.when(condLine1, field1.concat(" ")).otherwise(""),
DSL.when(condLine2, field2.concat(" ")).otherwise(""),
DSL.when(condLine3, field3.concat(" ")).otherwise(""),
DSL.when(condLine4, field4.concat(" ")).otherwise(""),
DSL.when(condLine5, field5.concat(" ")).otherwise(""),
DSL.when(condLine6, field6.concat(" ")).otherwise(""),
DSL.when(condLine7, field7.concat(" ")).otherwise(""),
DSL.when(condLine8, field8.concat(" ")).otherwise(""),
DSL.when(condLine9, field9.concat(" ")).otherwise("")).trim()
.as("fullAddress"));
is there any better alternative to JOOQ ( when = case ) condition clause?
I think the approach is sound. Of course, you probably shouldn't repeat all that logic all the time, but create a loop of the sort:
List<Field<String>> list = new ArrayList<>();
for (int i = 0; i < fields.size(); i++) {
list.add(DSL.when(conditions.get(i), (Field) fields.get(i)).otherwise(""));
}
customSelect.add(concat(list.toArray(new Field[0])).trim().as("fullAddress"));
I'm trying to append a string to an existing record in a MySQL Database:
UPDATE `db`.`tbl` SET field1 = IFNULL(field1, '') + ',' + '12/15/16: $50' WHERE field2 = 'xyz'
In MySQL, + is exactly what it suggests: addition. You are getting an error on arithmetic presumably because the strings are not converted to a number (fortunately -- otherwise you would silently get the wrong answer).
So, try this:
UPDATE `db`.`tbl`
SET field1 = CONCAT(COALESCE(field1, ''), ',', '12/15/16: $50')
WHERE field2 = 'xyz';
Or, if you don't want the comma if field1 is NULL:
UPDATE `db`.`tbl`
SET field1 = CONCAT(COALESCE(CONCAT(field1, ','), ''), '12/15/16: $50')
WHERE field2 = 'xyz';
to append in MySQL, use concat not + eg
select concat('something', 'something_else');
returns
somethingsomething_else
you can also use concat_ws (with separator)
select concat_ws('#','something', 'something_else')
returns
something#something_else
I have the following query. According to http://dev.mysql.com/doc/refman/5.0/en/case.html, null=null is false, thus the first case row will never occur. What would be an alternative query to accomplish this?
SELECT CASE c1
WHEN NULL THEN CONCAT("Hi",name," Your value is NULL")
WHEN "v1" THEN CONCAT("Hello ",name," The value is ",
CASE c2
WHEN "v11" THEN "bla"
WHEN "v12" THEN "bla bla"
END
,")")
WHEN "v2" THEN CONCAT("Howdy there ",name," Yep, the value is ",
CASE c3
WHEN "v21" THEN "beebop"
WHEN "v22" THEN "bopbee"
END
,")")
END
AS myLabel
FROM mytable
WHERE bla="bla";
So use the where <condition> form of case:
SELECT CASE WHEN c1 is NULL THEN CONCAT('Hi', name, ' Your value is NULL')
WHEN c1 = 'v1'
THEN CONCAT('Hello ', name, ' The value is ',
(CASE WHEN c2 = 'v11' THEN 'bla'
WHEN c2 = 'v12' THEN 'bla bla'
END), ')'
)
WHEN c1 = 'v21
THEN CONCAT('Howdy there ', name, ' Yep, the value is ',
(CASE WHEN c3 = 'v21' THEN 'beebop'
WHEN c3 = 'v22' THEN 'bopbee'
END), ')'
)
END
FROM mytable
WHERE bla = 'bla';
Also, use single quotes for string (and date) constants. Don't use them for anything else, like quoting delimiters.
An alternative would be to use COALESCE to get a default value in case the field is NULL, and then use that default for comparison where you are comparing with NULL in your present your query, like so:
SELECT CASE COALESCE(c1,'')
WHEN '' THEN CONCAT("Hi",name," Your value is NULL")
Of course, '' may be a legitimate value on it's own, in which case you need to use another value as default. Owing to this, I would personally recommend Gordon's solution as the way to go.
I am trying to figure out how to check if a field is NULL or empty. I have this:
SELECT IFNULL(field1, 'empty') as field1 from tablename
I need to add an additional check field1 != "" something like:
SELECT IFNULL(field1, 'empty') OR field1 != "" as field1 from tablename
Any idea how to accomplish this?
Either use
SELECT IF(field1 IS NULL or field1 = '', 'empty', field1) as field1
from tablename
or
SELECT case when field1 IS NULL or field1 = ''
then 'empty'
else field1
end as field1
from tablename
If you only want to check for null and not for empty strings then you can also use ifnull() or coalesce(field1, 'empty'). But that is not suitable for empty strings.
Using nullif does the trick:
SELECT ifnull(nullif(field1,''),'empty') AS field1
FROM tablename;
How it works: nullif is returning NULL if field is an empty string, otherwise returns the field itself. This has both the cases covered (the case when field is NULL and the case when it's an empty string).
Alternatively you can also use CASE for the same:
SELECT CASE WHEN field1 IS NULL OR field1 = ''
THEN 'empty'
ELSE field1 END AS field1
FROM tablename.
You can use the IFNULL function inside the IF. This will be a little shorter, and there will be fewer repetitions of the field name.
SELECT IF(IFNULL(field1, '') = '', 'empty', field1) AS field1
FROM tablename
You can create a function to make this easy.
create function IFEMPTY(s text, defaultValue text)
returns text deterministic
return if(s is null or s = '', defaultValue, s);
Using:
SELECT IFEMPTY(field1, 'empty') as field1
from tablename
By trimming and comparing, we ensure we also take care of empty or tab or space character content in the field.
SELECT
CASE
WHEN LTRIM(RTRIM(col_1))='' or col_1 IS NULL THEN 'Not available'
ELSE col_1
END AS col_alias
FROM
my_table
SELECT * FROM (
SELECT 2 AS RTYPE,V.ID AS VTYPE, DATE_FORMAT(ENTDT, ''%d-%m-%Y'') AS ENTDT,V.NAME AS VOUCHERTYPE,VOUCHERNO,ROUND(IF((DR_CR)>0,(DR_CR),0),0) AS DR ,ROUND(IF((DR_CR)<0,(DR_CR)*-1,0),2) AS CR ,ROUND((dr_cr),2) AS BALAMT, IF(d.narr IS NULL OR d.narr='''',t.narration,d.narr) AS NARRATION
FROM trans_m AS t JOIN trans_dtl AS d ON(t.ID=d.TRANSID)
JOIN acc_head L ON(D.ACC_ID=L.ID)
JOIN VOUCHERTYPE_M AS V ON(T.VOUCHERTYPE=V.ID)
WHERE T.CMPID=',COMPANYID,' AND d.ACC_ID=',LEDGERID ,' AND t.entdt>=''',FROMDATE ,''' AND t.entdt<=''',TODATE ,''' ',VTYPE,'
ORDER BY CAST(ENTDT AS DATE)) AS ta
If you would like to check in PHP , then you should do something like :
$query_s =mysql_query("SELECT YOURROWNAME from `YOURTABLENAME` where name = $name");
$ertom=mysql_fetch_array($query_s);
if ('' !== $ertom['YOURROWNAME']) {
//do your action
echo "It was filled";
} else {
echo "it was empty!";
}