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SQLite - UPSERT *not* INSERT or REPLACE
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Assuming three columns in the table: ID, NAME, ROLE
BAD: This will insert or replace all columns with new values for ID=1:
INSERT OR REPLACE INTO Employee (id, name, role)
VALUES (1, 'John Foo', 'CEO');
BAD: This will insert or replace 2 of the...
Transpose a data frame
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You can use the transpose function from the data.table library. Simple and fast solution that keeps numeric values as numeric.
library(data.table)
# get data
data("mtcars")
# transpose
t_mtcars <- transpose(mtcars)
# get row and colnames in order
colnames(t_mtc...
SQL join: selecting the last records in a one-to-many relationship
Suppose I have a table of customers and a table of purchases. Each purchase belongs to one customer. I want to get a list of all customers along with their last purchase in one SELECT statement. What is the best practice? Any advice on building indexes?
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How to place div side by side
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Using CSS display property - which can be used to make divs act like a table:
<div style="width: 100%; display: table;">
<div style="display: table-row">
<div style="width: 600px; display: table-cell;"> Left </div>
<div style="display: table-ce...
MySQL combine two columns into one column
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Try this, it works for me
select (column1 || ' '|| column2) from table;
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Create Pandas DataFrame from a string
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FYI - pd.read_table() is an equivalent function, just slightly better nomenclature: df = pd.read_table(TESTDATA, sep=";").
– wkzhu
Dec 6 '17 at 23:17
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Is there type Long in SQLite?
I want to create a table with the column type Long instead of Integer . Is it possible?
7 Answers
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Laravel Schema onDelete set null
Can't figure out how to set proper onDelete constraint on a table in Laravel. (I'm working with SqLite)
4 Answers
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Which MySQL datatype to use for an IP address? [duplicate]
... INT UNSIGNED
And INET_ATON and INET_NTOA to convert them:
INSERT INTO `table` (`ipv4`) VALUES (INET_ATON("127.0.0.1"));
SELECT INET_NTOA(`ipv4`) FROM `table`;
For IPv6 addresses you could use a BINARY instead:
`ipv6` BINARY(16)
And use PHP’s inet_pton and inet_ntop for conversion:
'INSER...
How do I concatenate const/literal strings in C?
...tressed enough. Misuse of strcat, strcpy, and sprintf are the heart of unstable/insecure software.
– plinth
Nov 21 '08 at 13:33
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