Oracle Database: PL/SQL cursor overview, oracleplI. cursor Concept
Literally, it refers to a swimming cursor, which is a handle or pointer pointing to the context area.
When performing the CRUD operation in the PL/SQL block, ORACLE allocates a
Today, we will briefly summarize the usage of cursor in PL/SQL.
Cursor category:
-- Explicit cursor-- Static cursor |
| -- Implicit cursorCursor |-- Strong type (Restriction), specifying the return type-- Dynamic Cursor -- ref cursor |-- Weak type
Basic Oracle cursor and basic oracle cursor
I. cursorThe cursor is used to process the multi-row records retrieved from the database (using the SELECT statement ). With the cursor, the program can process and traverse the entire record set returned
There are two types of cursors in Oracle: an explicit cursor, an implicit cursor. A display cursor is a cursor defined with the cursor...is command that handles multiple records returned by a query statement (SELECT), while an implicit cursor is a
1. What is a cursor?① Retrieve the result set from the table and point to a record for interaction at a time.② Operations in relational databases are performed on the complete set of rows.The row set returned by the SELECT statement includes all
1. IntroductionSQL is a collection-oriented language, and the result is generally a collection (with multiple records), and the PL-SQL variable is a scalar, a set of variables can only hold one record at a time. Many times the number of records for
1. Cursor conceptLiterally, it refers to a swimming cursor, which is a handle or pointer pointing to the context area.When performing the CRUD operation in the PL/SQL block, ORACLE allocates a context zone for it in the memory. The database language
1, what is a cursor? ① retrieves the result set from the table, and the mechanism from which each point points to a record for interaction.The operations in the ② relational database are performed on the complete rowset.The rowset returned by the
Cursor is a complex concept in the database field, because it contains shared cursor and session cursor. The two have different concepts and forms.The concept of shared cursor is easy to confuse with the cursor defined in SQL statements. This
Detailed description of Oracle CURSOR instance, oraclecursor CURSORI,Cursor Overview
Cursor is a data buffer provided by the database system in the memory. It stores the execution results of SQL statements.
Each cursor has a name. You can use SQL
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