I am new to databases and am posting a problem from work. I am creating a table in Aster Studio 6.0, but got an error about an ambiguous column. I ran the same query in Teradata SQL Assistant and did not get an error.
I have six tables with millions of rows named EDW.SWIFTIQ_TRANS_DTL, EDW.SWIFTIQ_STORE, EDW.SWIFTIQ_PROD, EDW.STORE_XREF, EDW.TDLNX_STR_OUTLT, and EDW.SURV_CWC.
EDW represents the original database, but the columns were labeled with aliases.
I did a trim() on the VARCHAR columns for saving spool space. For the error about TDLNX_RTL_OUTLT_NBR, I performed an INNER JOIN on similar columns from two different tables. Doing a preview in SQL Assistant, there was a temporary table with only one column called TDLNX_RTL_OUTLT_NBR.
Here’s the SQL query:
CREATE TABLE public.table_name
DISTRIBUTE BY HASH (SRC_SYS_PROD_ID) AS (
SELECT * FROM load_from_teradata(
ON public.load_from_teradata_dummy
TDPID(‘database_name')
USERNAME(’user_name')
PASSWORD(’ss')
QUERY ('SELECT e.TDLNX_RTL_OUTLT_NBR, e.OUTLT_ST_ADDR_TXT, e.STORE_OUTLT_ZIP_CD, d.TRANS_ID, d.TRANS_DT,
d.TRANS_TM, d.UNIT_QTY, d.SRC_SYS_STORE_ID, d.SRC_SYS_PROD_ID, d.SRC_SYS_NM, a.SRC_SYS_STORE_ID, a.SRC_SYS_NM, a.STORE_NM,
a.CITY_NM, a.ZIP_CD, a.ST_cd, p.SRC_SYS_PROD_ID, p.SRC_SYS_NM, p.UPC_CD, p.PROD_ID, f.SRC_SYS_STORE_ID, f.SRC_SYS_NM,
f.TDLNX_RTL_OUTLT_NBR, g.SURV_CWC_WSLR_CUST_PARTY_ID, g.AGE_CD, g.HIGH_END_ACCT_FLG, g.RACE_ETHNC_CD, g.OCCPN_CD
FROM EDW.SWIFTIQ_TRANS_DTL d
INNER JOIN EDW.SWIFTIQ_STORE a
ON trim( a.SRC_SYS_STORE_ID) = trim(d.SRC_SYS_STORE_ID)
INNER JOIN EDW.SWIFTIQ_PROD p
ON trim(p.SRC_SYS_PROD_ID) = trim(d.SRC_SYS_PROD_ID)
and p.SRC_SYS_NM = d.SRC_SYS_NM
INNER JOIN EDW.STORE_XREF f
ON trim(f.SRC_SYS_STORE_ID) = trim(a.SRC_SYS_STORE_ID)
INNER JOIN EDW.TDLNX_STR_OUTLT e
ON trim(e.TDLNX_RTL_OUTLT_NBR)= trim(f.TDLNX_RTL_OUTLT_NBR)
INNER JOIN EDW.SURV_CWC g
ON g.SURV_CWC_WSLR_CUST_PARTY_ID = e.WSLR_CUST_PARTY_ID
WHERE TRANS_DT between ''2015-01-01'' and ''2015-03-31''')
num_instances('4') ) );
ERROR: column reference 'TDLNX_RTL_OUTLT_NBR' is ambiguous.
EDIT: Forgot to include a description about the table aliases. a stands for EDW.SWIFTIQ_STORE, p for EDW.SWIFTIQ_PROD, f for EDW.STORE_XREF, e for EDW.TDLNX_STR_OUTLT, g for EDW.SURV_CWC, and d for EDW.SWIFTIQ_TRANS_DTL.
You will get the same error when you try CREATE TABLE AS SELECT in Teradata. There are three column names, SRC_SYS_NM & SRC_SYS_PROD_ID & SRC_SYS_STORE_ID, which are used multiple times (with different table aliases) within the SELECT.
Add column aliases to make those names unique, e.g. trans_SRC_SYS_NM instead of d.SRC_SYS_NM.
Additionally the TRIMs in the joins are a very bad idea. You will probably not save that much spool, but force the optimizer to redistribute all spools for join-preparation.
Related
I'm trying to join to tables using PROQ SQL. One of the columns I'm using for the join has a space in the column name. The query I'm using:
PROC SQL;
CREATE TABLE TEST AS
SELECT a.*, b.*
FROM TABLE_1 a
INNER JOIN TABLE_2 b
ON a.CONTNO = b."Contract Number";
RUN;
This is the error I'm getting:
ERROR 22-322: Syntax error, expecting one of the following: a name, *.
How do I fix this?
You just need to add square brackets around the Column name. For example:
b.[Contract Number]
Tips: Using alias (a, b) can be costly. When you only have one table to join, consider typing out the table rather than doing an alias.
I recently started using SAS, only receiving a basic training that didn't cover proc sql. I'd like to read up a bit more on SAS sql when I have the time.
For now, I found a solution to what I wanted to do, but I'm having difficulties understanding what is happening.
My issue started when I wanted to find out which subjects in my dataset have a certain value for all their records. I made use of my previously written snippet of code that I thought I understood. I just tried adding a couple more variables and group by statements:
data have;
input subject:$1. myvar:1. mycount:1.;
datalines;
a 1 1
a 0 2
a 0 3
b 1 1
b 0 2
b 1 3
c 1 1
c 1 2 /*This subject has myvar = 1 for all its observations*/
;
run;
*find subjects;
proc sql;
create table want as
/* select*/
/* distinct x.subject */
/* from */
(select distinct subject, count(myvar) as myvar_c
from have where myvar = 1 group by subject) x,
(select distinct subject, max(mycount) as max_c
from have group by subject) y
where x.subject = y.subject and x.myvar_c = y.max_c;
quit;
When removing the commented 'select distinct x.subject from' in the create table statement, the above code works as should.
However, I've previously also created another piece of code, to select all subjects in my dataset that have two types of records:
data have2;
input subject:$1. mytype:1.;
datalines;
a 1
a 0
a 0
b 1
b 0
b 1
c 1
c 1 /*This subject doesn't have two types of records in all its observations*/
;
run;
*Find subjects;
proc sql;
create table want2 as select
distinct x.subject from
have2 x,
(select distinct subject, count(distinct mytype) as mytype_c from have2 group by subject) y
where y.mytype_c = 2 and x.subject = y.subject;
quit;
Which is similar, but didn't require the additional select statement. The first code has 3 select statements, the second code only requires two select statements.
Can someone inform me why this is exactly required?
Or link me some good documentation that lists the specifications of these types of joins - can anyone also inform me of the specific name of this type of join where you only use a comma?
while I'm writing, also see that could've used my code I initially wrote to find subjects that have only 1 type of record and tweak it for my current issue >.< but still would like to know what is happening in the first example.
The SQL join construct
FROM ONE, TWO, THREE, …
is known as a CROSS JOIN and is a join without criteria. The comma (,) syntax is less prevalent today and the following construct is recommended
FROM ONE
CROSS JOIN TWO
CROSS JOIN THREE
The result set is a cartesian product and the number of rows is the product of the number of rows in the cross joined tables.
When the query has criteria (WHERE clause) the join is an INNER JOIN.
The SAS documentation for Proc SQL is a good starting point and includes examples.
joined-table Component
Joins a table with itself or with other tables or views.
…
Table of Contents
Syntax
Required Arguments
Optional Argument
Details
Types of Joins
Joining Tables
Table Limit
Specifying the Rows to Be Returned
Table Aliases
Joining a Table with Itself
Inner Joins
Outer Joins
Cross Joins
Union Joins
Natural Joins
Joining More Than Two Tables
Comparison of Joins and Subqueries
General tip:
If you want to fool around (fiddle) with SQL queries in a browser, try visiting
SQL Fiddle web site.
According to Hive's documentation it supports NOT IN subqueries in a WHERE clause, provided that the subquery is an uncorrelated subquery (does not reference columns from the main query).
However, when I attempt to run the trivial query below, I get an error FAILED: SemanticException Cartesian products are disabled for safety reasons.
-- sample data
CREATE TEMPORARY TABLE foods (name STRING);
CREATE TEMPORARY TABLE vegetables (name STRING);
INSERT INTO foods VALUES ('steak'), ('eggs'), ('celery'), ('onion'), ('carrot');
INSERT INTO vegetables VALUES ('celery'), ('onion'), ('carrot');
-- the problematic query
SELECT *
FROM foods
WHERE foods.name NOT IN (SELECT vegetables.name FROM vegetables)
Note that if I use an IN clause instead of a NOT IN clause, it actually works fine, which is perplexing because the query evaluation structure should be the same in either case.
Is there a workaround for this, or another way to filter values from a query based on their presence in another table?
This is Hive 2.3.4 btw, running on an Amazon EMR cluster.
Not sure why you would get that error. One work around is to use not exists.
SELECT f.*
FROM foods f
WHERE NOT EXISTS (SELECT 1
FROM vegetables v
WHERE v.name = f.name)
or a left join
SELECT f.*
FROM foods f
LEFT JOIN vegetables v ON v.name = f.name
WHERE v.name is NULL
You got cartesian join because this is what Hive does in this case. vegetables table is very small (just one row) and it is being broadcasted to perform the cross (most probably map-join, check the plan) join. Hive does cross (map) join first and then applies filter. Explicit left join syntax with filter as #VamsiPrabhala said will force to perform left join, but in this case it works the same, because the table is very small and CROSS JOIN does not multiply rows.
Execute EXPLAIN on your query and you will see what is exactly happening.
I am relatively new to bigquery and think I have an aliasing problem but can't work out what it is. Essentially, I have two tables and while the first table has the majority of the required information the second table has a date of birth that I need to join. I have written the below query and the two initial SELECT statements work in isolation and appear to return the expected values. However, when attempting to join the two tables I get an error stating:
Unrecognized name: t1_teams at [10:60]
WITH table_1 AS (SELECT competition_name, stat_season_name,
matchdata_Date, t1_teams.name, t1_players.Position, CAST(REGEXP_REPLACE(t1_players.uID, r'[a-zA-Z]', '') AS NUMERIC) AS Player_ID1, t1_players.First, t1_players.Last
FROM `prod.feed1`,
UNNEST(teams) AS t1_teams, UNNEST(t1_teams.Players) as t1_players),
table_2 AS (SELECT t2_players.uID AS Player_ID2, t2_players.stat_birth_date
FROM `prod.feed2`,
UNNEST(players) AS t2_players)
SELECT competition_name, stat_season_name, matchdata_Date, t1_teams.name, t1_players.Position, t1_players.uID, t1_players.First, t1_players.Last, t2_players.stat_birth_date
FROM table_1
LEFT JOIN table_2
ON Player_ID1 = Player_ID2
WHERE competition_name = "EPL"
AND stat_season_name = "Season 2018/2019"
Any help in steering me in the right direction would be greatly appreciated as my reading of the bigquery documentation and other searches have drawn a blank.
The problem is here:
WITH table_1 AS (
SELECT
competition_name,
stat_season_name,
matchdata_Date,
-- this line
t1_teams.name,
...
You're selecting t1_teams.name, so you end up with just name an an output column from the select list. If you want to refer to t1_teams later, then select that instead:
WITH table_1 AS (
SELECT
competition_name,
stat_season_name,
matchdata_Date,
-- this line
t1_teams,
...
I have a hive table A with 5 columns, the first column(A.key) is the key and I want to keep all 5 columns. I want to select 2 columns from B, say B.key1 and B.key2 and 2 columns from C, say C.key1 and C.key2. I want to join these columns with A.key = B.key1 and B.key2 = C.key1
What I want is a new external table D that has the following columns. B.key2 and C.key2 values should be given NULL if no matching happened.
A.key, A_col1, A_col2, A_col3, A_col4, B.key2, C.key2
What should be the correct hive query command? I got a max split error for my initial try.
Does this work?
create external table D as
select A.key, A.col1, A.col2, A.col3, A.col4, B.key2, C.key2
from A left outer join B on A.key = B.key1 left outer join C on A.key = C.key2;
If not, could you post more info about the "max split error" you mentioned? Copy+paste specific error message text is good.