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Update (SQL)

Index Update (SQL)

An SQL UPDATE statement changes the data of one or more records in a table. [1]

12 relations: Check constraint, Condition (SQL), Database index, From (SQL), Halloween Problem, Infinite loop, Null (SQL), PostgreSQL, Primary key, SQL, Table (database), Where (SQL).

Check constraint

A check constraint is a type of integrity constraint in SQL which specifies a requirement that must be met by each row in a database table.

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Condition (SQL)

A relational database management system uses SQL conditions or expressions in WHERE clauses and in HAVING clauses to SELECT subsets of data.

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Database index

A database index is a data structure that improves the speed of data retrieval operations on a database table at the cost of additional writes and storage space to maintain the index data structure.

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From (SQL)

The SQL From clause is the source of a rowset to be operated upon in a Data Manipulation Language (DML) statement.

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Halloween Problem

In computing, the Halloween Problem refers to a phenomenon in databases in which an update operation causes a change in the physical location of a row, potentially allowing the row to be visited more than once during the operation.

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Infinite loop

An infinite loop (or endless loop) is a sequence of instructions in a computer program which loops endlessly, either due to the loop having no terminating condition, having one that can never be met, or one that causes the loop to start over.

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Null (SQL)

Null (or NULL) is a special marker used in Structured Query Language to indicate that a data value does not exist in the database.

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PostgreSQL, often simply Postgres, is an object-relational database management system (ORDBMS) with an emphasis on extensibility and standards compliance.

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Primary key

In the relational model of databases, a primary key is a specific choice of a minimal set of attributes (columns) that uniquely specify a tuple (row) in a relation (table).

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SQL (S-Q-L, "sequel"; Structured Query Language) is a domain-specific language used in programming and designed for managing data held in a relational database management system (RDBMS), or for stream processing in a relational data stream management system (RDSMS).

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Table (database)

A table is a collection of related data held in a structured format within a database.

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Where (SQL)

A WHERE clause in SQL specifies that a SQL Data Manipulation Language (DML) statement should only affect rows that meet specified criteria.

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SQL Update, Sql update, UPDATE (SQL), Update sql.


[1] https://en.wikipedia.org/wiki/Update_(SQL)

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