sql update multiple columns

1. What is the cursor? Oracle uses two types of cursor: explicit cursor and implicit cursor. No matter how many records are returned by the statement, PL/SQL implicitly declares a cursor for each SQL command, such as UPDATE, DELETE, and INSERT. To manage SQL statement processing, you must implicitly define a cursor fo

System.Data.OleDb.OleDbConnection(ConnectionString); cn.Open(); System.Data.DataSet ds = new System.Data.DataSet(); System.Data.OleDb.OleDbDataAdapter da = new System.Data.OleDb.OleDbDataAdapter("SELECT * From a11", cn); System.Data.OleDb.OleDbDataAdapter da1 = new System.Data.OleDb.OleDbDataAdapter("SELECT * From b11", cn); System.Data.OleDb.OleDbCommandBuilder cb = new System.Data.OleDb.OleDbCommandBuilder(da); System.Data.OleDb.OleDbCommandBuilder cb

Insert/update/delete operation insert (insert) 1. Simple Form Note: A new object is added to the corresponding set using the insertonsubmit method and submitted to the database using submitchanges. NorthwindDataContext db = new NorthwindDataContext();var newCustomer = new Customer{ CustomerID = "MCSFT", CompanyName = "Microsoft", ContactName = "John Doe", ContactTitle = "Sales Manager", Address = "1 Microsoft Way", City = "Redmond",

immediately when the locked object is not needed, equal to the serializable transaction isolation levelNOLOCK statement execution does not emit a shared lock, allowing dirty reads, equal to the READ UNCOMMITTED transaction isolation LEVELPaglock with multiple page locks where a table lock is usedREADPAST let SQL Server skip any locking lines, perform transactions, apply to READ UNCOMMITTED transaction isol

From: http://www.oecp.cn/hi/zhaolihong/blog/1980 When SQL Server was recently used in projects, it was found that frequent updates and frequent queries cause deadlocks in high concurrency. We usually know that if two transactions insert or modify data to a table at the same time, it will occur when the X lock of the table is requested, and it is already held by the other party. Because the lock is not obtained, the subsequent commit cannot be execute

Update is one of the most common SQL statements. The following describes three usage methods of update statements for your reference. I. Environment:MySQL-5.0.41-win32Windows XP professional2. Establish a test environment:Drop table if exists t_test;Create table t_test (Bs bigint (20) not null auto_increment,Username varchar (20) not null,Password varchar (20) de

selected, put the primary key value recorded IN the row into the IN ClauseBuilder. AppendFormat ("'{0}',", this. GridView1.DataKeys [row. RowIndex]. Value. ToString ());I ++;Continue;}Continue;}If (builder. ToString (). Length = 0) // if no data row exists IN the IN clause, a prompt is displayed.{StrHelper. Alert ("no data row is selected. Please reselect it! ");Return;}// Remove the last "," in the StringBuilder objectBuilder. Remove (builder. ToString (). LastIndexOf (","), 1 );// Assemble

It is best to use bcp if you just need to insert data in large quantities, if you need to insert, delete, and update the proposed use of SqlDataAdapter I tested high efficiency, and in general, these two meet the demand bcp method Copy Code code as follows: Bulk Insert data (2000 per batch) Have adopted the whole thing control public static void BulkCopy (String connstring, String tablename, DataTable DT) { using (SqlConnection conn =

Example of a trigger codes: Code of the insert, delete, and update trigger: Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/-->-- DBO. trgroups. SQL If exists ( Select * From sysobjects where Name = 'trgroups' and type = 'tr ') Begin Drop trigger trgroups If not exists ( Select * From sysobjects where Name = 'trgroups' and type = 'tr ') Print 'drop trgroups s

Label: Update statement The Update statement is used to modify the data in the table.Grammar:UPDATE table name SET column name = new value WHERE Column name = valuePerson: LastName FirstName Address City Gates Bill Xuanwumen 10 Beijing Wilson Champs-elysees To update