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Export from sqlite to csv using shell script
... sqlite3 command options:
sqlite3 -header -csv my_db.db "select * from my_table;" > out.csv
This makes it a one-liner.
Also, you can run a sql script file:
sqlite3 -header -csv my_db.db < my_script.sql > out.csv
Use sqlite3 -help to see the list of available options.
...
Drop data frame columns by name
...multiple variables:
within(df, rm(x, y))
Or if you're dealing with data.tables (per How do you delete a column by name in data.table?):
dt[, x := NULL] # Deletes column x by reference instantly.
dt[, !"x"] # Selects all but x into a new data.table.
or for multiple variables
dt[, c("x","y...
read.csv warning 'EOF within quoted string' prevents complete reading of file
...ng 403 back with read.csv(). Adding quote = "" got me up to 410 rows. read.table() does no better. I wonder what else can be tried...
– Hack-R
Aug 21 '14 at 15:12
2
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How can I get a list of all functions stored in the database of a particular schema in PostgreSQL?
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After some searching, I was able to find the information_schema.routines table and the information_schema.parameters tables. Using those, one can construct a query for this purpose. LEFT JOIN, instead of JOIN, is necessary to retrieve functions without parameters.
SELECT routines.routine_name, pa...
How can I call a custom Django manage.py command directly from a test driver?
...for a Django manage.py command that does a backend operation on a database table. How would I invoke the management command directly from code?
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UITableView - change section header color
How can I change color of a section header in UITableView?
31 Answers
31
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Cannot insert explicit value for identity column in table 'table' when IDENTITY_INSERT is set to OFF
...tionId that is an identity column.
You can turn on identity insert on the table like this so that you can specify your own identity values.
SET IDENTITY_INSERT Table1 ON
INSERT INTO Table1
/*Note the column list is REQUIRED here, not optional*/
(OperationID,
OpDescription...
Split data frame string column into multiple columns
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5 years later adding the obligatory data.table solution
library(data.table) ## v 1.9.6+
setDT(before)[, paste0("type", 1:2) := tstrsplit(type, "_and_")]
before
# attr type type1 type2
# 1: 1 foo_and_bar foo bar
# 2: 30 foo_and_bar_2 foo ba...
How to do a regular expression replace in MySQL?
I have a table with ~500k rows; varchar(255) UTF8 column filename contains a file name;
13 Answers
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How can I use mySQL replace() to replace strings in multiple records?
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At a very generic level
UPDATE MyTable
SET StringColumn = REPLACE (StringColumn, 'SearchForThis', 'ReplaceWithThis')
WHERE SomeOtherColumn LIKE '%PATTERN%'
In your case you say these were escaped but since you don't specify how they were escaped, let's s...