This is the table in which I want to insert values in the first row of the c_mean_rl and m_mean_rl columns.
I want to insert values of the avg column in the c_mean_rl and m_mean_rl columns.
Related
I would like to write an INSERT INTO script that takes all the rows from table B (let's assume table B has 300 rows) and uses their ids as foreign key values for some column of table A (the one I want to insert to), so I will end up with 300 new rows inserted into table A.
How can I achieve that in PostgreSQL?
INSERT INTO "table_A" ("id_in_table_B")
SELECT
"id"
FROM "table_B"
I have a table with a column that contains array of numbers like : ['1','3','45'];
And was looking for a way to select the column value from the second index so that I get ['3','45']
Is there any way to do this in PostgreSQL?
Question: Is there a way to insert a row in PostgreSQL table using the default values for all columns without specifying any column name?
Background: If I have a table with two columns that both have default values (or simply accept NULL), I can omit the column name when I insert a row if I wish the value for that column to be the default value. For instance:
CREATE TABLE test_table ( column1 TEXT, column2 TEXT );
I can insert into the table by only specifying a value for column1 or column2 and the missing column will be populated with the default value (NULL in this case):
INSERT INTO test_table (column1) VALUES ('foo');
INSERT INTO test_table (column2) VALUES ('bar');
The above will result in two rows: [('foo', NULL), (NULL, 'bar')]. However, if I want to use the default value for both columns, it seems that I have to specify at least one column name and explicitly give it the default value. The follow commands are all legal:
INSERT INTO test_table (column1) VALUES (DEFAULT);
INSERT INTO test_table (column2) VALUES (DEFAULT);
INSERT INTO test_table (column1, column2) VALUES (DEFAULT, DEFAULT);
I was unable to create a valid command that allowed me to omit all column names. The following attempts are all illegal:
INSERT INTO test_table;
INSERT INTO test_table () VALUES ();
Is there a way to do this or is it explicitly forbidden? I wasn't able to find any documentation for a case like this. Thanks!
I found that there is special syntax for this exact use-case:
INSERT INTO test_table DEFAULT VALUES;
I have a simple table (4 text columns, and an ID column). I am trying to import my CSV file which has no ID column.
In Postico I have the schema setup as such:
DROP TABLE changes;
CREATE TABLE changes(
id SERIAL PRIMARY KEY,
commit_id TEXT,
additions INTEGER,
deletions INTEGER,
file_id TEXT
);
CREATE TEMP TABLE tmp_x AS SELECT * FROM changes LIMIT 0;
COPY tmp_x(commit_id,additions,deletions,file_id) FROM '/Users/George/git-parser/change_file' (format csv, delimiter E'\t');
INSERT INTO changes SELECT * FROM tmp_x
ON CONFLICT DO NOTHING;
DROP TABLE tmp_x;
But I am getting the error ERROR: null value in column "id" violates not-null constraint
You need to specify the columns:
COPY tmp_x (commit_id, additions, deletions, file_id)
FROM '/Users/George/git-parser/change_file' (format csv, delimiter E'\t');
The order of columns specified in the copy statement must obviously match the order of the columns in the input file.
You need to change your insert statement as well.
INSERT INTO changes SELECT * FROM tmp_x
will insert all columns from tmp_x into the target table, but as you did not define the id column as serial in the tmp_x table, nothing got generated and null values were inserted. And your insert statement just copies those null values.
You need to skip the id column in the insert statement:
INSERT INTO changes (commit_id,additions,deletions,file_id)
SELECT commit_id,additions,deletions,file_id
FROM tmp_x
ON CONFLICT DO NOTHING;
You can actually remove the id column from tmp_x
i have to insert multiple records into a table and in the mean time needed to insert the identity column of the first table in to another table.Can i do it avoiding loop?
Edited
i have two tables named StudentMaster and StudentSujects.
First Table structure is (StudentID int Identity(1,1),StudentName varchar(100))
Second table structure is (SubjectID int Identity(1,1),StudentID int,SubjectName varchar(100)).
StudentID in the 'StudentSujects' table is the Identity column of first table 'StudentMaster'.
INSERT INTO StudentMaster
(
StudentName
)
SELECT StudentName
FROM OPENXML(#hDoc,'/XML/Students')
WITH( StudentName varchar(100) 'StudentName')
I am inserting multiple records in to the first table using the above query.I the mean time i have to insert the identity column of each row in to the second table.
You can use the OUTPUT clause to output multiple columns/rows on an INSERT operation into a table variable.
Assuming your table that you're inserting into has an IDENTITY column called ID, you could have code something like this:
DECLARE #InsertedData TABLE (NewID INT, SomeOtherColumn.....)
INSERT INTO dbo.YourTable(Col1, Col2, ..., ColN)
OUTPUT INTO #InsertedData(NewID, SomeOtherColumn) Inserted.ID, Inserted.OtherColumn
VALUES(Val11, Val12, ..., Val1N),
(Val21, Val22, ..., Val2N),
....
(ValM1, ValM2, ..., ValMN)
Of course, you need to have something that allows you to identify which row in your second table to insert which value into - that's entirely dependent on your situation (and you didn't offer any explanation of that in your question).
But basically, using the OUTPUT clause, you can capture as much information as you need, including the newly assigned IDENTITY values, so that you can then do your second insert based on that information.