When you create a table (or an index), you can tell PostgreSQL to store the object in a specific tablespace by including a TABLESPACE tablespacename clause, like this: CREATE TABLE joes_video.customers(. You can’t give ownership to another user at the time you create the table, but you can change it later using the ALTER TABLE.OWNER TO command (described later). If you want the table to be created in some other schema, you can prefix the table name with the schema qualifier, for example: CREATE TABLE joes_video.customers(. (If you are using a version older than 7.3, your copy of PostgreSQL does not support schemas). If you are using PostgreSQL 7.3 or later, the customers table is created in the first schema in your search path. When you execute this command, the customers table is created in the database that you are connected to. This means that you can’t create a table whose name is the same as an existing data type. When you create a table, PostgreSQL automatically creates a new data type 2 with the same name as the table. A table name must meet the naming criteria described earlier in this chapter. This command creates a permanent table named customers. Here is the command that you used to create the customers table: CREATE TABLE customers ( You’ve created some simple tables in the first two chapters it’s time to talk about some of the more advanced features of the CREATE TABLE command. Now let’s move down one level in the PostgreSQL storage hierarchy and talk about creating and dropping tables. VALUES is syntactically allowed anywhere that SELECT is allowed, as it is treated as a SELECT statement internally by the grammar.The previous section described how to create and drop databases. Postgres=# insert into foo values (3,300) Postgres=# insert into foo values (2,200) Postgres=# insert into foo values (1,100) postgres=# create table foo(n int primary key, n1 int) The most common case for using VALUES is with the INSERT command. Since this is not a standard format, you must explicitly specify some meaningful column names.įor example: db=# SELECT * FROM (VALUES (1,'XYZ'),(2,'abc')) AS t (id, data) It is also possible to use the ORDER BY, LIMIT, and OFFSET arguments with VALUES: postgres=# values (1,'XYZ'),(2,'ABC') order by 1 limit 1 īy default, PostgreSQL assigns the column names as column1, column2, etc. Any difference in the values being provided will throw an error.įor example: postgres=# values (1,'xyz'),(2),(3,'def') ĮRROR: VALUES lists must all be the same length In order to ensure that a constant table works, the lists must all have the same number of columns. This above result is equivalent to the following syntax, which is both more complicated and hard to maintain in a production environment: postgres=# select 1,'XYZ' This will return a table of 2 columns and 2 rows. The supported syntax is VALUES ( expression ) Įxpression (or a constant) is used to compute and insert a value at the indicated place (rows) in the table.īelow is a simple example of the constant table that we will use to explain the table as well as how we can work with it. In PostgreSQL, the VALUES keyword provides a way to create a constant table. The idea of a constant table is to form a table with constant values that can be used in a query without the need of creating and populating a table on disk. We will cover the following topics at a high level: In this post, we are going to look at what a constant table in PostgreSQL is and how we can use it. It covers the following topics with examples: SUMMARY: This article discusses constant tables in PostgreSQL.
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