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How to update an entire column in sqlite? [duplicate]
(1 answer)
Closed 1 year ago.
How to set all values in a column to empty (null)?. To reset the value of a nullable column for every row in a table.
Just ignore the WHERE clause would do the trick. How to change a value in a column on a SQLite database?
UPDATE table_name SET column_name = NULL
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SQLite3 UNIQUE constraint failed error
(2 answers)
Closed 6 days ago.
Unfortunately I get an error when I wanted to put the values for my attributes. I don't know exactly what the problem is. For Info : I have previously created 8 tables successfully and i use SQLite Online.Here is the picture
I hope that someone can solve my problem.
If a table has a UNIQUE constraint, it means the value of a column (or set of columns) must be unique, i.e. cannot be repeated for different rows in the table.
You're trying to insert a new record that breaks that constraint, i.e. the new row contains values in the constraint columns that already exist in the table with the same combination of values.
For example:
CREATE TABLE t1 (id INT, firstname, surname TEXT, UNIQUE (id, surname));
INSERT INTO t1 VALUES (1, 'John', 'Doe');
INSERT INTO t1 VALUES (1, 'Bob', 'Doe'); -- UNIQUE constraint failed: t1.id, t1.surname
This question already has answers here:
SQLite DateTime comparison
(14 answers)
Closed 3 months ago.
Given the table Use, defined as
CREATE TABLE Use(date TEXT NOT NULL, id TEXT PRIMARY KEY);
I want to make a query to find "All uses before today", however SQLite is not behaving as I expect and return the wrong value.
I tried to query using my table as such:
SELECT * FROM Use WHERE date <= datetime('now')
The problem here is that date might not be in the same format that datetime returns.
You need first to convert the date to use the same format, by using the datetime function on it as well, and then you can compare both correctly:
SELECT * FROM Use where datetime(date) <= datetime('now')
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How to use SQL Order By statement to sort results case insensitive?
(3 answers)
Closed 2 years ago.
Why is the following query working inverse? I'd expect that asc order them in alphabetical order..
Apply CAPS to the commands and apply 'NOCASE' function like:
SELECT * FROM giochi ORDER BY nomegioco NOCASE (ASC)
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How to select the last column of dataframe
(8 answers)
Closed 4 years ago.
Hello I have a data frame in python jupyter notebook and need to take the last column of it. How Can I take the last column of data frame?
Use iloc index, it should do the trick
df.iloc[:,-1]
It works on such way that : selects all rows and -1 selects last column
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ROWID INTEGER PRIMARY KEY AUTOINCREMENT - How to insert values?
(5 answers)
Closed 6 years ago.
A similar question has been asked before, but the query is embedded in java and perhaps less clear to a total novice who would be asking this type of question.
I think the 'rowid' column is not auto-populating/auto-incrementing. Table, insert statement, and error code as follows:
CREATE TABLE T (rowid INTEGER PRIMARY KEY, c1 REAL, c2 REAL);
insert into T values (8,9);
Error code in my DB Browser is:
table T has 3 columns but 2 values were supplied: insert into T values (1,2);
I have other code that is very similar but not producing this error. Any help is greatly appreciated! Thanks!!
This isn't a SQLite problem, it's a problem with your DB browser enforcing that values for all three columns must always be present.
One option to get around this would be to insert NULL for the rowid column. This should force SQLite to assign the next logical value, which is the behavior you want anyway:
INSERT INTO T values (NULL, 1, 2);