update column from another table in oracle

-------------------------------------------------------------------| Id | Operation | Name | Rows | Cost (%CPU) | Time |-------------------------------------------------------------------| 0 | SELECT STATEMENT | | 1 | 135 (2) | 00:00:02 || 1 | SORT AGGREGATE | | 1 | | || 2 |TABLE ACCESS full| TEST | 41790 | 135 (2) | 00:00:02 |-------------------------------------------------------------------In conclusion, it seems that if the

Sometimes the development of table structure design, whether the table field is empty is too casual, such as id1 = id2, if the field is allowed to be empty, because the Oracle empty value is not equal to the null value, unexpected results may be obtained. In addition, NULL affects the execution plan of oracle. The foll

In the process of doing the project today, it is found that a field in a table in the development library has many values that are empty, while the value of the field in the test library is there.So, what is the way to update the value of the field in the test library to the development library?This is easier to solve in SQL Server, and the method is not known in Oracle.Workarounds for similar issues in SQL

Modify the Data Type of the column corresponding to the primary key of an Oracle database table When upgrading our product from SPC100 to SPC200, because the data type of the database table column has changed, you need to write an SQL script to complete the Database Upgrade

Modify the Data Type of the column corresponding to the primary key of the Oracle database table. When upgrading our product from SPC100 to SPC200, because the data type of the database table column has changed, you need to write an SQL script to complete the Database Upgra

(post_content CLOB);Update Post_info Set post_content = Empty_clob ();ALTER TABLE Post_info Modify (post_content not NULL);COMMENT on COLUMN "Dbvop". " Post_info "." Post_content "is' Notice content ';Commit ---------------In addition: How to change the column syntax of a class that is not NULL CLOB type to NULL: ALTE

columns is a one-time DDL operation that generates a large number of Redo Log records; Data Tables are locked for a long time, which hinders the production system. When a data column is added, an exclusive lock is added to the data table, which hinders other DML operations; Destroys the original storage structure, resulting in a large amount of Row Migration data. When you try to add each data row to the d

following error:ORA-01427: Single-line subquery returns multiple rows3. Through the above analysis, simple UPDATE statements do not solve the abnormal situation encountered. So we can use the merge as follows: Merge into table1 using table2 in (Table1.idd = Table2.idd) When matched then update set Table1.val = Table2.valAlthough can solve the E1 situation, but encountered E3 situation, still error, as fol

modifies the table-level constraints of Oracle, don't confuse it.Delete ColumnWhen you delete a column in a table, you can delete one column at a time and delete multiple columns at once.Delete one column at a timeThe syntax form

Sometimes, to improve the performance of database tables, you need to reorganize the tables in the Oralce database. For example, in an Oracle database Sometimes, to improve the performance of database tables, you need to reorganize the tables in the Oralce database. For example, in an Oracle database Oracle Database is one of the most complex databases so fa

In Oracle, there are times when you need to update another table with one table. The following are examples of implementations: 1. Create a table test_a CREATE TABLE Test_a (ID Number (19),Name VARCHAR2 (20),Age Number (3)) 2.

Oracle has the following two tables: update the val value of the row with the same id value in Table tab1 and that in Table tab2 to the val value in table 2.Select * from tab1; Select * from tab2 The most common mistake is: update