insert-update

Given the schema below: create table TBL1 (ID varchar2(100) primary key not null, MATCH_CRITERIA varchar2(100)); create table TBL2 (ID varchar2(100) primary key not null, MATCH_CRITERIA varchar2(100)); create table TBL_RESULT (ID varchar2(100) primary key not null, TBL1_ID varchar2(100), TBL2_ID varchar2(100)); create unique index UK_TBL_RESULT_TBL1_ID on TBL_RESULT(TBL1_ID); create unique index UK_TBL_RESULT_TBL2_ID on TBL_RESULT(TBL2_ID); create sequence SEQ_TBL_RESULT; insert into TBL1 VALUES('1', '1'); insert into TBL1 VALUES('2', '1'); insert into TBL1 VALUES('3', '1'); insert into TBL2

I need to perform a left join of two tables in netezza during an update. How can i achieve this ? Left join with three tables are working but not with two tables. UPDATE table_1 SET c2 = t2.c2 FROM table_1 t1 LEFT JOIN table_2.t1 ON t1.c1=t2.c1 LEFT JOIN table_3 t3 ON t2.c1=t3.c1 this works but UPDATE table_1 SET c2 = t2.c2 FROM table_1 t1 LEFT JOIN table_2.t1 ON t1.c1=t2.c1 this says like trying to update multiple columns. Thanks, Manirathinam. When performing an UPDATE TABLE with a join in Netezza, it's important to understand that the table being updated is always implicitly INNER JOINed

I have a question regarding performance of SQL Server. Suppose I have a table persons with the following columns: id , name , surname . Now, I want to insert a new row in this table. The rule is the following: If id is not present in the table, then insert the row. If id is present, then update. I have two solutions here: First: update persons set id=@p_id, name=@p_name, surname=@p_surname where id=@p_id if @@ROWCOUNT = 0 insert into persons(id, name, surname) values (@p_id, @p_name, @p_surname) Second: if exists (select id from persons where id = @p_id) update persons set id=@p_id, name=@p

hii every one I need to add one column to my existing table so how can i alter table in sqlite database through the obj c ,i am using the following code for inserting data into table in the same way how can i write updata table method - (void) InsertRecord { if(addStmt == nil) { const char *sql = "insert into tbl_Users(FirstName,MiddleName) Values(?,?)"; if(sqlite3_prepare_v2(database, sql, -1, &addStmt, NULL) != SQLITE_OK) NSAssert1(0, @"Error while creating add statement. '%s'", sqlite3_errmsg(database)); } sqlite3_bind_text(addStmt, 1, [strFirstName UTF8String], -1, SQLITE_TRANSIENT);

When using a min/max-heap algorithm, priorities may change. One way to handle this is to removal and insert the element to update the queue order. For priority queues implemented using arrays, this can be a performance bottleneck that seems avoidable, especially for cases when the change to priority is small. Even if this is not a standard operation for a priority queue , this is a custom implementation which can be modified for my needs. Are there well known best-practice methods for updating elements in the min/max-heap? Background Info: I'm no expert in binary-trees, I inherited some code