大约有 43,000 项符合查询结果（耗时：0.0273秒） [XML]
How to prepend a string to a column value in MySQL?
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You can use the CONCAT function to do that:
UPDATE tbl SET col=CONCAT('test',col);
If you want to get cleverer and only update columns which don't already have test prepended, try
UPDATE tbl SET col=CONCAT('test',col)
WHERE col NOT LIKE ...
Comparing strings with == which are declared final in Java
... question about strings in Java. The following segment of simple code just concatenates two strings and then compares them with == .
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How to merge two arrays in JavaScript and de-duplicate items
... just merge the arrays (without removing duplicates)
ES5 version use Array.concat:
var array1 = ["Vijendra", "Singh"];
var array2 = ["Singh", "Shakya"];
console.log(array1.concat(array2));
ES6 version use destructuring
const array1 = ["Vijendra","Singh"];
const array2 = ["Singh", "Shakya"...
Combine multiple Collections into a single logical Collection?
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With Guava, you can use Iterables.concat(Iterable<T> ...), it creates a live view of all the iterables, concatenated into one (if you change the iterables, the concatenated version also changes). Then wrap the concatenated iterable with Iterables.unmodi...
How many String objects will be created when using a plus sign?
...iteLine(result);
}
then the compiler seems to emit the code using String.Concat as @Joachim answered (+1 to him btw).
If you define them as constants, e.g.:
const String one = "1";
const String two = "2";
const String result = one + two + "34";
or as literals, as in the original question:
Str...
push multiple elements to array
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@BluE if you want to merge two arrays just use array.concat()
– Florent Arlandis
Feb 26 at 16:45
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How do you add an array to another array in Ruby and not end up with a multi-dimensional result?
... [1,2,'foo','bar'].
I'm doubtless forgetting some approaches, but you can concatenate:
a1.concat a2
a1 + a2 # creates a new array, as does a1 += a2
or prepend/append:
a1.push(*a2) # note the asterisk
a2.unshift(*a1) # note the asterisk, and that a2 is the receiver
or...
Comparing two dataframes and getting the differences
...to find changes, but symmetric difference. For that, one approach might be concatenate dataframes:
>>> df = pd.concat([df1, df2])
>>> df = df.reset_index(drop=True)
group by
>>> df_gpby = df.groupby(list(df.columns))
get index of unique records
>>> idx = [...
Limit text length to n lines using CSS
...lor: black;
width: 250px; /* Could be anything you like. */
}
.text-concat {
position: relative;
display: inline-block;
word-wrap: break-word;
overflow: hidden;
max-height: 3.6em; /* (Number of lines you want visible) * (line-height) */
line-height: 1.2em;
text-align:just...
Using LIMIT within GROUP BY to get N results per group?
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You could use GROUP_CONCAT aggregated function to get all years into a single column, grouped by id and ordered by rate:
SELECT id, GROUP_CONCAT(year ORDER BY rate DESC) grouped_year
FROM yourtable
GROUP BY id
Result:
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