Postgresql insert into from select how to#
Postgresql insert into from select code#

I don't like that nested dblink, but AFAIK I can't reference to tblB in dblink_exec body. If my understanding is correct (postgres has tbla and dbtest has tblb and you want remote insert with local select, not remote select with local insert as above): psql dbtest I just saw your revised question (closed as duplicate, or just very similar to this). You can make it as prepared statement if you want and it works as well: PREPARE migrate_data (integer) AS One can insert a single row at a time or several rows as a result of a. PostgreSQL has record pseudo-type (only for function's argument or result type), which allows you query data from another (unknown) table. The PostgreSQL INSERT INTO statement allows one to insert new rows into a table.

INSERT INTO tblB (time) VALUES (5000), (2000) ĬREATE TABLE tblA (id serial, time integer) įROM dblink('dbname=dbtest', 'SELECT id, time FROM tblB') For example: psql dbtestĬREATE TABLE tblB (id serial, time integer)

As Henrik wrote you can use dblink to connect remote database and fetch result. Don’t forget that you can select fixed values if no column from the query has the info ( INSERT INTO X(p,c,age) SELECT personname, cityname, 23 FROM. The number of columns inserted to must match the number of columns selected. However, I trust that the general pattern shown first will suffice for your learning write a SELECT that shows the data you want to insert, then simply write INSERT INTO table(columns) above it. If you just want to mix every person with every city you can do: INSERT INTO employee(personname,cityname)īut be warned, two people and two cities will cause 4 rows to be inserted, and so on (20 people and 40 cities, 800 rows. Provide eg a cityname in Person (because it seems more likely that one city has many person) then you can do INSERT INTO employee(personname,cityname)īut even then, the tables are related between themselves and don’t need the third table so it’s perhaps something of an academic exercise only, not something you’d do in the real world SELECT INTO define a new table from the results of a query Synopsis WITH RECURSIVE withquery. In your case there isn’t really anything to join on because your one-column tables have no column in common. The general pattern for turning a select that has two base tables giving info, into an insert is: INSERT INTO table(column,list,here)

Postgresql insert into from select code#

There doesn’t appear to be any obvious relationship between city and person which will make your life hard Insert some data in the table and use this query to select data from the first partition: SELECT FROM employeep1 Running the above code displays the data stored in the first partition: Use the following query to get the data stored in the second partition: SELECT FROM employeep2 That’s all about using PARTITION BY in PostgreSQL.

Postgresql insert into from select how to#

The textbook I have for class doesn't dive into sub-queries like this and I can't find any examples similar enough to mine such that I can understand how to adapt them for this use case. Notice in the last block of code, where I'm doing an INSERT into the employee table, I don't know how to string together multiple SELECT sub-queries to get both the existing records from the person and city table such that I can create a new employee entry with attributes as such: create employee entry referencing existing records The target column names can be listed in any order. One can insert one or more rows specified by value expressions, or zero or more rows resulting from a query. Create a employee table w/ForeignKey referenceĮname VARCHAR(255) REFERENCES person(pname) NOT NULL,Įcity VARCHAR(255) REFERENCES city(cname) NOT NULL, Description INSERT inserts new rows into a table. Create a city table + insert single row I am learning SQL (postgres) and am trying to insert a record into a table that references records from two other tables, as foreign keys.īelow is the syntax I am using for creating the tables and records: - Create a person table + insert single row