There are two tables in my database. I am trying to update a column in table2 by setting it equal to one of the columns in table1. I've already looked at this answer visual foxpro - need to update table from another table
And tried to do this on my code, however, I kept having a syntax error on UPDATE table2. Why?
Here is what I have.
ALTER TABLE table2;
ADD COLUMN base2 B(8,2);
UPDATE table2
WHERE table2.itemid=table1.itemid from table1;
SET table2.base2=table1.base;
The simplest syntax is:
update table2 from table1 where table2.itemid = table1.itemid ;
set table2.base2 = table1.base
You could also add more fields to update separated by commas, i.e.
... set table2.base2 = table1.base, table2.this = table1.that
Using 'standard' VFP language syntax and RELATED Tables, you could quite easily do the following:
USE Table1 IN 0 EXCLUSIVE
SELECT Table1
INDEX ON ID TAG ID && Create Index on ID field
USE Table2 IN 0
SELECT Table2
SET RELATION TO ID INTO Table1
REPLACE ALL Table2.ID WITH Table1.ID FOR !EMPTY(Table2.ID)
You might want to spend some time looking over the free, on-line tutorial videos at: Learn Visual Foxpro # garfieldhudson.com
The videos named:
* Building a Simple Application - Pt. 5
and
* Q&A: Using Related Tables In A Report
Both discuss using VFP's language to work with Related Tables
Good Luck
Use join
Update table2 b
Join table1 a on b. Itemid=a.itemid
Set b. Base2=a.base
Related
Need to add two following insert statements:
insert into table1(schema, table_name, table_alias)
values ('ref_owner','test_table_1','tb1');
insert into table1(schema, table_name, table_alias)
values ('dba_owner','test_table_2','tb2');
Question is how can I make those two insert statements re-runnable meaning, if those two insert statement are compiled again, it should throw row exists error or something along those lines...?
Additional notes:
1. I've seen examples of Merge in Oracle however, thats only when you're using two tables to match records. In this case im only using a single table.
2. The table does not have any primary, unique or foreign keys - only check constraints on one of the columns.
Any help is highly appreciated.
You can use a MERGE statement, as follows:
MERGE into table1 t1
USING (SELECT 'ref_owner' AS SCHEMA_NAME, 'test_table_1' AS TABLE_NAME, 'tb1' AS ALIAS_NAME FROM DUAL
UNION ALL
SELECT 'dba_owner', 'test_table_2', 'tb2' FROM DUAL) d
ON (t1.SCHEMA = d.SCHEMA_NAME AND
t1.TABLE_NAME = d.TABLE_NAME)
WHEN NOT MATCHED THEN
INSERT (SCHEMA, TABLE_NAME, TABLE_ALIAS)
VALUES (d.SCHEMA_NAME, d.TABLE_NAME, d.ALIAS_NAME)
Best of luck.
You should have a primary key, especially when you want to check for duplicate records and data integrity.
Provide a primary key for your table, or, if you somehow do not want to do that, create a unique constraint for all of the columns in the table, so no duplicate rows are possible.
I have created a new table in hive (T1) with columns c1,c2,c3,c4. I want to populate data into this table by querying from other existing tables(T2,T3).
E.g c1 and c2 come from a query run on T2 & the other columns c3 and c4 come from a query run on T3.
Is this possible in hive ? I have done immense research but still am unable to find a solution to this
Didn't something like this work?
create table T1 as
select t2.c1, t2.c2, t3.c3, t3.c4 from (some query against T2) t2 JOIN (some query against T3) t3
Obviously replace JOIN with whatever is needed. I assume some join between T2 and T3 is possible or else you wouldn't be putting their columns alongside each other in T1.
According to the hive documentation, you can use the following syntax to insert data:
INSERT INTO TABLE tablename1 [PARTITION (partcol1=val1, partcol2=val2 ...)] select_statement1 FROM from_statement;
Be careful that:
Values must be provided for every column in the table. The standard SQL syntax that allows the user to insert values into only some columns is not yet supported. To mimic the standard SQL, nulls can be provided for columns the user does not wish to assign a value to.
So, I would make a JOIN between the two existing table, and then insert only the needed values in the target table playing around with SELECT. Or maybe creating a temporary table would allow you to have more control over the data. Just remember to handle the problem with NULL, as stated in the official documentation. This is just an idea, I guess there are other ways to achieve what you need, but could be a good place to start from.
I created a table using select with a union, as follows:
create table tableC as
select column1, column2 from tableA
union all
select column1, column2 from tableB
The resulting table (tableC) has inherited none of the constraints from tableA or tableB. Why weren't the constraints copied to the new table?
Using select ... as ... to create a table never copies constraints. If you want the new table to inherit constraints from the original tables, you must create the new constraints manually.
As #Davek points out, not null constraints will get copied from a single table select ... as .... I imagine that's because they are both column attributes and constraints. However, once the column has more than one source, it is reasonable that Oracle would not try to apply that constraint.
In response to the follow-up question "would it be possible to give tableC the same constraints either from tableA or tableB, after a CTAs?":
Of course it's possible, but there's no single command to do it. You could write a procedure that used dynamic SQL to copy the constraints. However, unless you're looking to automate this behavior, it'll generally be easier to extract the DDL using an IDE and change the table name.
I have two tables like bellow shows figures
I need to select records as bellow shown figure. with AH_ID need to join in second table and ATT_ID will be the column header and ATT_DTL_STR_VALUE need to get as that column relevant value
Required output
Sounds like you have an Entity-Attribute-Value data model which relational DBs aren't the best at modeling. You may want to look into a key-value store.
However, as Justin suggested, if you're using 11g you can use th pivot clause as follows:
SELECT *
FROM (
SELECT T1.AH_ID, T1.AH_DESCRIPTION, T2.ATT_ID, T2.ATT_DTL_STR_VALUE
FROM T1
LEFT OUTER JOIN T2 ON T1.AH_ID = T2.AH_ID
)
PIVOT (MAX(ATT_DTL_STR_VALUE) FOR (ATT_ID) IN (1));
This statement requires you to hard-code in ATT_ID however there are ways to do it dynamically. More info can be found here.
Everywhere I look I can find how to update a table from data in another table but I am not looking for that. I have two tables TABLE1 and TABLE2. TABLE1 has a column PULLDATE and a column JOBNMBR. TABLE2 has a column JOBNMBR and a column PROJECT. The two tables link at the JOBNMBR column. I need to do a bulk update to TABLE1.PULLDATE per a project number, but that project number is stored in TABLE2.PROJECT.
Using VisualStudio 2005 and in VB code not C+, does anyone know the code (if there is any) that links the tables and allows me to update all TABLE1.PULLDATE records grouped by TABLE2.PROJECT? I will be providing the trigger to update using a textbox [TxtBox_Pulldate] and a nearby button [Button_UpdatePulldate].
Thanks a bunch
Chuck Vensel
I think I understand that you want to update Table1 given a matching column in Table2?
You write the SQL update just as you would the SELECT except replace the SELECT clause with the UPDATE clause.
UPDATE Table1
SET
[PULLDATE] = your_value
FROM
Table1
JOIN Table2
ON Table2.[JOBNMBR] = Table1.[JOBNMBR]
WHERE
Table2.[PROJECT] = your_project_ID