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What is the string concatenation operator in Oracle?
What is the string concatenation operator in Oracle SQL?
5 Answers
5
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How to remove leading and trailing whitespace in a MySQL field?
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I downvoted. Testcase: SELECT CONCAT('"', TRIM(" hello world "), '"') AS `trimmed value` FROM DUAL gives the wanted output "hello world". While the replace variant dangerously removes the space as word separator: SELECT CONCAT('"', REPLACE(" hello world "...
Adding two Java 8 streams, or an extra element to a stream
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If you add static imports for Stream.concat and Stream.of, the first example could be written as follows:
Stream<Foo> stream = concat(stream1, concat(stream2, of(element)));
Importing static methods with generic names can result in code that becomes dif...
How to append something to an array?
...ant to add the items of one array to another array, you can use firstArray.concat(secondArray):
var arr = [
"apple",
"banana",
"cherry"
];
arr = arr.concat([
"dragonfruit",
"elderberry",
"fig"
]);
console.log(arr);
Update
Just an addition to this answer if you want to prepend...
Import multiple csv files into pandas and concatenate into one DataFrame
I would like to read several csv files from a directory into pandas and concatenate them into one big DataFrame. I have not been able to figure it out though. Here is what I have so far:
...
How to remove multiple indexes from a list at the same time? [duplicate]
...e for the different ways so I performed a test on removing 5000 items from 50000 in all 3 generally different approaches, and for me numpy was the winner (if you have elements that fit in numpy):
7.5 sec for the enumerated list comprehension [4.5 sec on another PC]
0.08 sec for deleting items in r...
How do you use the “WITH” clause in MySQL?
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declare recursive_table_tmp varchar(120);
set recursive_table_next = concat(recursive_table, "_next");
set recursive_table_union = concat(recursive_table, "_union");
set recursive_table_tmp = concat(recursive_table, "_tmp");
# Cleanup any previous failed runs
SET @str =
CONCAT("...
Most efficient way to concatenate strings?
What's the most efficient way to concatenate strings?
17 Answers
17
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How to use GROUP_CONCAT in a CONCAT in MySQL
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select id, group_concat(`Name` separator ',') as `ColumnName`
from
(
select
id,
concat(`Name`, ':', group_concat(`Value` separator ',')) as `Name`
from mytbl
group by
id,
`Name`
) tbl
group by id;
You can see it im...
Append column to pandas dataframe
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Or pd.concat([dat1, dat2], axis=1) in this case.
– DSM
Dec 16 '13 at 3:35
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