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An identity column differs from a primary key in that its values are managed by the server and usually cannot be modified. In many cases an identity column is used as a primary key; however, this is not always the case. It is a common misconception that an identity column will enforce uniqueness; however, this is not the case. If you want to ...
A surrogate key (or synthetic key, pseudokey, entity identifier, factless key, or technical key [citation needed]) in a database is a unique identifier for either an entity in the modeled world or an object in the database. The surrogate key is not derived from application data, unlike a natural (or business) key. [1]
This is a standalone product for developers to create data models for MySQL, SQL Server, Oracle, PostgreSQL and SQLite databases. Navicat Data Modeler allows users to visually design database structures, perform reverse/forward engineer process, import table structures from ODBC data sources, generate SQL files and print models to files, etc.
In the relational model of databases, a primary key is a designated attribute that can reliably identify and distinguish between each individual record in a table.The database creator can choose an existing unique attribute or combination of attributes from the table (a natural key) to act as its primary key, or create a new attribute containing a unique ID that exists solely for this purpose ...
A commonly used CREATE command is the CREATE TABLE command. The typical usage is: CREATE TABLE [table name] ( [column definitions]) [table parameters] The column definitions are: A comma-separated list consisting of any of the following; Column definition: [column name] [data type] {NULL | NOT NULL} {column options} Primary key definition ...
Create/alter table: Yes - can create table, alter its definition and data, and add new rows; Some - can only create/alter table definition, not data; Browse table: Yes - can browse table definition and data; Some - can only browse table definition; Multi-server support: Yes - can manage from the same window/session multiple servers
In relational databases a virtual column is a table column whose value(s) is automatically computed using other columns values, or another deterministic expression. Virtual columns are defined of SQL:2003 as Generated Column, [1] and are only implemented by some DBMSs, like MariaDB, SQL Server, Oracle, PostgreSQL, SQLite and Firebird (database server) (COMPUTED BY syntax).
The following assumes the syntax is a whole table row in one source line starting with a pipe and with double pipe between cells. It does not work with partially compressed table wikitext either (such as for tables with row headers). A table with any non-compressed wikitext can be completely compressed by pasting the table into Excel2Wiki. Do ...