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How can I see all users in Oracle?

SELECT * FROM user_users;

  1. Oracle ALL_USERS. The ALL_USERS view lists all users that visible to the current user. However, this view doesn’t describe the users.
  2. Oracle DBA_USERS. The DBA_USERS view describes all user in the Oracle database.
  3. Oracle USER_USERS. THe USER_USERS view describes the current user:

How can I see all tables in SQL?

The easiest way to see all tables in the database is to query the all_tables view: SELECT owner, table_name FROM all_tables; This will show the owner (the user) and the name of the table.20

How do I see all columns in SQL?

You can use following query to list all columns or search columns across tables in a database. USE AdventureWorks GO SELECT t.name AS table_name, SCHEMA_NAME(schema_id) AS schema_name, c.name AS column_name FROM sys. tables AS t INNER JOIN sys. columns c ON t.

How do I view a SQL query table?

This first query will return all of the tables in the database you are querying.

  1. SELECT TABLE_NAME FROM INFORMATION_SCHEMA. TABLES.
  2. SELECT TABLE_NAME, COLUMN_NAME FROM INFORMATION_SCHEMA.
  3. SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.
  4. IF EXISTS( SELECT * FROM INFORMATION_SCHEMA.
  5. IF EXISTS( SELECT * FROM INFORMATION_SCHEMA.

How do I view a SQL database?

In Object Explorer, connect to an instance of the SQL Server Database Engine, and then expand that instance. Expand Databases, right-click the database to view, and then click Properties. In the Database Properties dialog box, select a page to view the corresponding information.5

What are triggers in SQL?

A trigger is a special type of stored procedure that automatically runs when an event occurs in the database server. DML triggers run when a user tries to modify data through a data manipulation language (DML) event. SQL Server lets you create multiple triggers for any specific statement.30

What is a view vs a table?

A view is a virtual table. A view consists of rows and columns just like a table. The difference between a view and a table is that views are definitions built on top of other tables (or views), and do not hold data themselves. If data is changing in the underlying table, the same change is reflected in the view.

How do I retrieve a row in SQL?

The syntax is: SELECT column1, column2 FROM table1, table2 WHERE column2=’value’; In the above SQL statement: The SELECT clause specifies one or more columns to be retrieved; to specify multiple columns, use a comma and a space between column names.13

How do I select top 5 rows in SQL?

SQL SELECT TOP Clause

  1. SQL Server / MS Access Syntax. SELECT TOP number|percent column_name(s) FROM table_name;
  2. MySQL Syntax. SELECT column_name(s) FROM table_name. LIMIT number;
  3. Example. SELECT * FROM Persons. LIMIT 5;
  4. Oracle Syntax. SELECT column_name(s) FROM table_name. WHERE ROWNUM <= number;
  5. Example. SELECT * FROM Persons.

Is Rownum stored in database?

4 Answers. Both, rownum and rowed are pseudo columns. For each row in the database, the ROWID pseudocolumn returns the address of the row. For each row returned by a query, the ROWNUM pseudocolumn returns a number indicating the order in which Oracle selects the row from a table or set of joined rows.15

How do I get top 3 records in SQL?

SQL TOP, LIMIT, FETCH FIRST or ROWNUM Clause

  1. SQL Server / MS Access Syntax: SELECT TOP number|percent column_name(s) FROM table_name.
  2. MySQL Syntax: SELECT column_name(s) FROM table_name.
  3. Oracle 12 Syntax: SELECT column_name(s)
  4. Older Oracle Syntax: SELECT column_name(s)
  5. Older Oracle Syntax (with ORDER BY): SELECT *

How do you find top 10 salary in SQL?

TO FIND NTH HIGHEST SALARY USING CTE

  1. SELECT*FROM [DBO].[EMPLOYEE] ORDER BY SALARY DESC.
  2. GO.
  3. WITH RESULT AS.
  4. (
  5. SELECT SALARY,
  6. DENSE_RANK() OVER (ORDER BY SALARY DESC) AS DENSERANK.
  7. FROM EMPLOYEE.
  8. )

How do I get the first 10 records in SQL?

To select first 10 elements from a database using SQL ORDER BY clause with LIMIT 10. Insert some records in the table using insert command. Display all records from the table using select statement. Here is the alternate query to select first 10 elements.19

How do I select top 1000 rows in SQL?

In order to SELECT or EDIT all tables open SSMS, under Tools, click Options as shown in tha image below: Then expand SQL Server Object Explorer, and select Command: Then change those 200 and 1000 values to 0 for both options.18

How do I get last 10 rows in SQL?

The following is the syntax to get the last 10 records from the table. Here, we have used LIMIT clause. SELECT * FROM ( SELECT * FROM yourTableName ORDER BY id DESC LIMIT 10 )Var1 ORDER BY id ASC; Let us now implement the above query.23

How do I change last 200 rows in SQL?

If you right click on any result of “Edit Top 200 Rows” query in SSMS you will see the option “Pane -> SQL”….

  1. Go to Tools menu -> Options -> SQL Server Object Explorer.
  2. Expand SQL Server Object Explorer.
  3. Choose ‘Commands’
  4. For ‘Value for Edit Top Rows’ command, specify ‘0’ to edit all rows.

How do I edit 1000 rows in SQL?

By default in SSMS, you can select 1000 Rows and Edit 200 Rows.

  1. If you would like to change the default value then go to SSMS > Tools > Options:
  2. In the Options dialog box, highlight SQL Server Object Explorer and change the default values to any number as per your requirements.

How do I edit rows in SQL?

To modify table data through a view

  1. In Object Explorer, expand the database that contains the view and then expand Views.
  2. Right-click the view and select Edit Top 200 Rows.
  3. You may need to modify the SELECT statement in the SQL pane to return the rows to be modified.

How do I modify a row in SQL?

To update data in a table, you need to:

  1. First, specify the table name that you want to change data in the UPDATE clause.
  2. Second, assign a new value for the column that you want to update.
  3. Third, specify which rows you want to update in the WHERE clause.

How do I edit specific rows in SQL?

3 Answers. Use the “Edit top 200” option, then click on “Show SQL panel”, modify your query with your WHERE clause, and execute the query. You’ll be able to edit the results.28

How do you modify a column in SQL?

To change the data type of a column in a table, use the following syntax:

  1. SQL Server / MS Access: ALTER TABLE table_name. ALTER COLUMN column_name datatype;
  2. My SQL / Oracle (prior version 10G): ALTER TABLE table_name. MODIFY COLUMN column_name datatype;
  3. Oracle 10G and later: ALTER TABLE table_name.

How do you edit in SQL?

Select the “SQL Query (input)” tab and click on the “Edit SQL” button. “Edit SQL Statement” dialog will appear. Type a new query definition or modify the existing query and click “OK”.

How do I update a column in MySQL?

MySQL UPDATE

  1. First, specify the name of the table that you want to update data after the UPDATE keyword.
  2. Second, specify which column you want to update and the new value in the SET clause.
  3. Third, specify which rows to be updated using a condition in the WHERE clause.

Can I use join in update query?

The most easiest and common way is to use join clause in the update statement and use multiple tables in the update statement. Here we can see that using join clause in update statement. We have merged two tables by the use of join clause.

Is null query in MySQL?

Let’s look at an example of how to use MySQL IS NULL in a SELECT statement: SELECT * FROM contacts WHERE last_name IS NULL; This MySQL IS NULL example will return all records from the contacts table where the last_name contains a NULL value.

Can we use limit in update query?

Yes, it is possible to use UPDATE query with LIMIT in MySQL.20