Getting:
Table IDs may contain letters, numbers, and underscores.
Trying to save the view as:
final-162619.final_project.GDELTblockchainVIEW
Using standard SQL for my query and it outputs a simple joined table just fine. It looks to be an issue with the hyphen and periods, is there a way to escape those? Standard [] brackets didn't seem to work
I don't believe saving the view as final-162619.final_project.GDELTblockchainVIEW is possible in BigQuery because of the fact you've got periods and hyphens in it.
The API also clearly states this:
You can quote your project id, dataset name, and table name with backticks. You have to quote them individually. For example:
SELECT `billing-address`
FROM `my-project`.`shopify-import`.`the-orders`
(If you have underscores instead of hyphens they don't need quoting.)
Related
I'm new to hiveSQL and I'm trying to extract a value from the column col_a from the data df which is in this format:
\\\"id\\\":\\\"101_12345\\\"
I only need to extract 101_12345, but underscore makes it hard to satisfy my need. I tried using regexp_extract(col_a, '(\\d+)[_](\\d+)') but only outputs 101.
Could I get some help with regexp? Thank you
Simple solution: You don't need the two brackets.
Here's a working solution: '\\d+[_]\\d+'
When you put tokens into parentheses, the regex engine will group its match together, separate from the complete match. So the final result will comprise the complete match, and two extra matches representing the one before and after the underscore. To avoid this, just remove the brackets as you don't really need them.
In the future, if you want to group a regex together but don't want the result to contain it separately, use a non-capturing group given by (?:).
Here's a demo of what your code resulted in, hosted at regex101.com
I want to create a database containing multiple tables using postgres 11 and i'm currently creating a table which contain brackets in the heading of the column (as shown as follows).
Table - supp_details
supp_id|supp_name | supp_weight(Kg)|
Can i add units to the heading and what is the proper way to do so with sql?
I'm a fresher to query writing, so please help me with this.
You could place the column name in quotes, e.g. use "supp_weight(Kg)", but it is best to avoid placing special characters or keywords as object names. Instead, I suggest using the following name:
supp_weight_kg
It is just a single string requiring no escaping, and makes it clear what the units are. A better option might be to just use supp_weight, and maybe just keep a note somewhere that the column uses kilograms as the unit by default.
You will need to use quoted identifiers but I strongly recommend not to do that:
create table supp_details
(
supp_id integer,
supp_name text,
"supp_weight(kg)" integer
);
Adding bracket symbols into your column names is possible but probably a bad idea. If you want to micromanage the name just for display purposes of the end result, you should probably do it in an alias, using the AS keyword.
SELECT supp_id, supp_name, supp_weight AS "supp_weight(Kg)" FROM ...
Or add the decorations on the client side before it displays the results.
I want to create a SQL Server database that will hold thousands of tables who's names will reflect stock ticker names. For example, '0099-OL.HK' is a company's ticker name. Many of the stocks I'm creating tables for have special characters in them just like that.
I've read that special characters in table names should be avoided, but I still don't know why. SQL Server lets you use special characters in table names if you enclose the name with brackets, e.g., 'CREATE TABLE [0099-OL.HK] ...'.
Should I use the ticker names as their table names, or should I avoid using their special characters?
This will lead to no end of problems. The reason SQL Server allows names with spaces and special characters is because people migrate from databases that allow these characters in their names. If you must do this replace all special characters with _ like so: TN0099_OL_HK (TN for ticker name) so users can type sql without using the brackets.
It is bad practice to do so, since not every library might be able to process the table name correctly.
Avoid using special characters, spaces, and leading numbers in database names, table names, and column names.
For the full Rules for Regular Identifiers: Database Identifiers - docs
I am running below query in Teradata :
sel requesttext from dbc.tables
where tablename='old_employee_table'
Result:
alter table DB_NAME.employee_table,no fallback ;
I want to get below result using SQL:
DB_NAME.employee_table
Requesttext can be:
create set table DB_NAME.employee_table;
DB Name and table can occur anywhere in the result. Since .(dot) is joining them that's why i want to split with .(dot).
Basically I need sql which can result me surrounding values of .(dot)
I want DBName and Tablename in result.
I'm not a Teradata person, but this should work for both strings given so far, as long as teradata's regexp_substr() supports positive look-behind and positive look-ahead assertions (I might have the Teradata syntax wrong, so a little tweaking may be needed):
SELECT REGEXP_SUBSTR(requesttext, '(?<= )(\w+\.\w+)(?=[,$]?)', 1, 1)
FROM dbc.tables
WHERE tablename='old_employee_table'
See the regex101 example. Hopefully it translates to Teradata easily.
The regex looks for and returns the words either side of and including the period, when preceded by a space, and followed by an optional comma or the end of the line.
You could do this with either regexp_substr() or strtok().
As Jamie Zawinski said:
Some people, when confronted with a problem, think "I know, I'll use
regular expressions." Now they have two problems.
So I would go with the strtok() method. Also I'm lazy and regular expressions are hard.
Function strtok() takes three arguments:
The string being split
The delimiter to split the string
The number of the token to grab.
To get at the <database>.<table> from that string that is returned in your query, we can split by a space, grab the third token, then split that by a comma and grab the first token.
That would look like:
SELECT strtok(strtok(requestText,' ',3),',',1)
FROM dbc.tables
WHERE tablename='old_employee_table'
I have two SQLite tables, that I would love to join them on a name column. This column contains accented characters, so I am wondering how can I compare them for join. I would like the accents dropped for the comparison to work.
You can influence the comparison of characters (such as ignoring case, ignoring accents) by using a Collation. SQLLite has only a few built in collations, although you can add your own.
SqlLite, Data types, Collating Sequences
SqlLite, Define new Collating Sequence
EDIT:
Given that it seems doubtful if Android supports UDFs and computed columns, here's another approach:
Add another column to your table, normalizedName
When your app writes out rows to your table, it normalizes name itself, removing accents and performing other changes. It saves the result in normalizedName.
You use normalizedName in your join.
As the normalization function is now in java, you should have few restrictions in coding it. Several examples for removing accents in java are given here.
There is an easy solution, but not very elegant.
Use the REPLACE function, to remove your accents. Exemple:
SELECT YOUR_COLUMN FROM YOUR_TABLE WHERE replace(replace(replace(replace(replace(replace(replace(replace(
replace(replace(replace( lower(YOUR_COLUMN), 'á','a'), 'ã','a'), 'â','a'), 'é','e'), 'ê','e'), 'í','i'),
'ó','o') ,'õ','o') ,'ô','o'),'ú','u'), 'ç','c') LIKE 'SEARCH_KEY%'
Where SEARCH_KEY is the key word that you wanna find on the column.
As mdma says, a possible solution would be a User-Defined-Function (UDF). There is a document here describing how to create such a function for SQLite in PHP. You could write a function called DROPACCENTS() which drops all the accents in the string. Then, you could join your column with the following code:
SELECT * FROM table1
LEFT JOIN table2
ON DROPACCENTS(table1.column1) = DROPACCENTS(table2.column1)
Much similar to how you would use the UCASE() function to perform a case-insensitive join.
Since you cannot use PHP on Android, you would have to find another way to create the UDF. Although it has been said that creating a UDF is not possible on Android, there is another Stack Overflow article claiming that a content provider could do the trick. The latter sounds slightly complicated, but promising.
Store a special "neutral" column without accented characters and compare / search only this column.