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How do I create test and train samples from one dataframe with pandas?
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scikit learn's train_test_split is a good one.
from sklearn.model_selection import train_test_split
train, test = train_test_split(df, test_size=0.2)
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List of foreign keys and the tables they reference
..._name of the table ALL_CONSTRAINTS. This will give you the info you want:
SELECT a.table_name, a.column_name, a.constraint_name, c.owner,
-- referenced pk
c.r_owner, c_pk.table_name r_table_name, c_pk.constraint_name r_pk
FROM all_cons_columns a
JOIN all_constraints c ON a.owner ...
Query to list number of records in each table in a database
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If you're using SQL Server 2005 and up, you can also use this:
SELECT
t.NAME AS TableName,
i.name as indexName,
p.[Rows],
sum(a.total_pages) as TotalPages,
sum(a.used_pages) as UsedPages,
sum(a.data_pages) as DataPages,
(sum(a.total_pages) * 8) / 1024 as To...
How to determine the number of days in a month in SQL Server?
...er of days in the month.
DECLARE @ADate DATETIME
SET @ADate = GETDATE()
SELECT DAY(EOMONTH(@ADate)) AS DaysInMonth
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How can I suppress column header output for a single SQL statement?
...in batch (using the mysql command-line binary). I want one of my several SELECT statements to not print the column headers, just the selected records. Is this possible?
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如何查看Oracle用户的SQL执行历史记录？ - 数据库(内核) - 清泛网 - 专注C/...
如何查看Oracle用户的SQL执行历史记录？select * from v$sqlarea t order by t LAST_ACTIVE_TIME desc注意 ：执行此语句等等一些相关的语句 必须具有DBA 的权限 虽然
select * from v$sqlarea t order by t.LAST_ACTIVE_TIME desc
注意 ：执行此语句等等一些相...
Remove all spaces from a string in SQL Server
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Simply replace it;
SELECT REPLACE(fld_or_variable, ' ', '')
Edit:
Just to clarify; its a global replace, there is no need to trim() or worry about multiple spaces for either char or varchar:
create table #t (
c char(8),
v varchar(8))...
jQuery select all except first
In jQuery how do I use a selector to access all but the first of an element? So in the following code only the second and third element would be accessed. I know I can access them manually but there could be any number of elements so thats not possible. Thanks.
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Convert text into number in MySQL query
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This should work:
SELECT field,CONVERT(SUBSTRING_INDEX(field,'-',-1),UNSIGNED INTEGER) AS num
FROM table
ORDER BY num;
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How to set OnClickListener on a RadioButton in Android?
...oGroup group, int checkedId) {
// checkedId is the RadioButton selected
}
});
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