I have a stored function that generates an identity name based on a set of parameters like this:
.create function
with (docstring = 'Returns the table name for the specified data log provider.')
GetTableName(param1: string, param2: string)
{
// Some string cleansing and concatenation
let tableName = strcat(system, source);
tableName
}
I want to use this function to create a table. Tried the following options with no success:
.create table GetTableName('value1', 'value2') (Timestamp: datetime)
.create table [GetTableName('value1', 'value2')] (Timestamp: datetime)
I'm guessing the command expects the table name to be a string literal. Is there any way to accomplish this?
Control commands that create tables cannot include query execution (and vise versa: queries cannot run control commands).
The restriction exists for security reasons.
You can achieve the scenario using client code and having two calls:
1) Derive table name
2) Generate table create command and send it to the server.
Related
Problem Statement : I would like write a BigQuery UDF to de·crypt table columns
Setup :
PII information is encrypted in table columns with tink package
KEK (Key Encryption Key ) is sitting in KMS
DEK (data encryption Key) is sitting in Cloud storage
I have written BigQuery EXTERNAL Table to access DEK json i.e. select encryptedKeyset from my_project.my_dataset.external_table_for_decrypted_keys will give me required dek key
This is my sample code
CREATE OR REPLACE FUNCTION my_proj.my_dataset.udf_decrypt_column(table_name string, column_name string)
BEGIN
DECLARE KMS_RESOURCE_NAME STRING;
DECLARE FIRST_LEVEL_KEYSET STRING;
SET KMS_RESOURCE_NAME= "gcp-kms://projects/dev/locations/us/keyRings/dev/cryptoKeys/dev-kek";
SET FIRST_LEVEL_KEYSET = (select encryptedKeyset from my_project.my_dataset.external_table_for_decrypted_keys`);
SELECT
AEAD.DECRYPT_STRING(KEYS.KEYSET_CHAIN(KMS_RESOURCE_NAME,
from_base64(FIRST_LEVEL_KEYSET)),
from_base64(column_name),
"") as decrypted_name
FROM table_name
Issues/Question :
Declare variables do not work in Functions (while they work in procedures). So my question is how to assign values to variables in UDF
How to run SQL & assign value to variable in UDF. In my case I want to fetch column encryptedKeyset from external_table_for_decrypted_keys & assign to FIRST_LEVEL_KEYSET (in declare section)
Any idea/pointer how to achieve this ? Thanks in advance for your reply.
I'm having some strange feeling abour sqlite3 parameters that I would like to expose to you.
This is my query and the fail message :
#query
'SELECT id FROM ? WHERE key = ? AND (userid = '0' OR userid = ?) ORDER BY userid DESC LIMIT 1;'
#error message, fails when calling sqlite3_prepare()
error: 'near "?": syntax error'
In my code it looks like:
// Query is a helper class, at creation it does an sqlite3_preprare()
Query q("SELECT id FROM ? WHERE key = ? AND (userid = 0 OR userid = ?) ORDER BY userid DESC LIMIT 1;");
// bind arguments
q.bindString(1, _db_name.c_str() ); // class member, the table name
q.bindString(2, key.c_str()); // function argument (std::string)
q.bindInt (3, currentID); // function argument (int)
q.execute();
I have the feeling that I can't use sqlite parameters for the table name, but I can't find the confirmation in the Sqlite3 C API.
Do you know what's wrong with my query?
Do I have to pre-process my SQL statement to include the table name before preparing the query?
Ooookay, should have looked more thoroughly on SO.
Answers:
- SQLite Parameters - Not allowing tablename as parameter
- Variable table name in sqlite
They are meant for Python, but I guess the same applies for C++.
tl;dr:
You can't pass the table name as a parameter.
If anyone have a link in the SQLite documentation where I have the confirmation of this, I'll gladly accept the answer.
I know this is super old already but since your query is just a string you can always append the table name like this in C++:
std::string queryString = "SELECT id FROM " + std::string(_db_name);
or in objective-C:
[#"SELECT id FROM " stringByAppendingString:_db_name];
I am trying to reproduce the SQL Server default NEWID() value for a UNIQUEIDENTIFIER column in SQLite. It produces a UUID as a default for the column.
How can I do that in SQLite?
I found this page (Is there UID datatype in SQLITE if Yes then how to generate value for that) where they use a select statement but it is no good for DEFAULT.
NOTE : I am using the SQLite version implemented for browsers as I am using it through ionic and the cordova-sqlite plugin. So this does not contain all the features provided by SQLite and more importantly this does not contain the RANDOM function.
Yes, you can use create function to add a UUID function. By default you'd have to write it in C, but many SQLite drivers have a way to add functions in their native language. Here's an example in Perl using DBD::SQLite.
use strict;
use warnings;
use v5.10;
use DBI;
use Data::UUID;
# Connect to the database.
my $dbh = DBI->connect("dbi:SQLite:dbname=test.db", "", "", { RaiseError => 1});
# Create uuid() which calls Perl to generate a uuid.
$dbh->sqlite_create_function("uuid", 0, sub { Data::UUID->new->create_str });
# Create a table using uuid() as the default.
$dbh->do(q[drop table if exists foo]);
$dbh->do(q[
create table foo (
id int primary key default (uuid()),
name text
)
]);
# Insert some rows using the default id.
$dbh->do(q[
insert into foo (name) values ("you"), ("me")
]);
# Print out the rows.
my $rows = $dbh->selectall_arrayref(q[select * from foo]);
for my $row (#$rows) {
say "$row->[0], $row->[1]";
}
And the result is.
E9768488-834F-11E6-AA60-F143DC5749B0, you
E976B69C-834F-11E6-AA60-F143DC5749B0, me
I'm attempting to setup a search function from a string a user types. (ex: "John Doe" or "Doe, John")
I was thinking I would use Replace(SearchString, ",", "") to get rid of the commas the user might enter, and then use Split(SearchString, " ") to get all the words into an array. Once they're in the array I would execute a Stored Procedure on each of the terms and build a DataTable with the results.
Below is what I'm wanting to use for executing my stored procedure.
oCommand = DataAccess.GetSQLCommand("MyStoredProcedure", CommandType.StoredProcedure, SourceServer.ConnectionLocal)
oCommand.Parameters.AddWithValue("#MySearchString", SearchString)
oAdapter = New SqlDataAdapter(oCommand)
oAdapter.Fill(MyDataTable)
Now I'm thinking the "SearchString" I will assign while looping through my array of words... but this doesn't seem like the right way to do this. Maybe it is but I don't know how to append my next result to the previous DataTable either.
There are some great ideas for using arrays and Lists in SQL Server on this page - http://www.sommarskog.se/arrays-in-sql-2005.html
I personally find the XML method the most useful;
http://www.sommarskog.se/arrays-in-sql-2005.html#XML
An example of how I've used this in the past is;
DECLARE #indata nvarchar(max)
DECLARE #hDoc int
SET #indata = '
<ROOT>
<SearchTerm code="Test search term"></SearchTerm>
<SearchTerm code="Other search term"></SearchTerm>
<SearchTerm code="Next search term"></SearchTerm>
</ROOT>'
CREATE TABLE #searchTerm (
code varchar(40)
)
EXEC sp_xml_preparedocument #hDoc OUTPUT, #indata
INSERT Into #searchTerm
SELECT code
FROM OPENXML(#hDoc, '/ROOT/SearchTerm',1)
WITH (code varchar(50))
EXEC sp_xml_removedocument #hDoc
-- Use the data in #searchTerm as needed in your query
SELECT * FROM MyTable WHERE searchValue IN (SELECT code FROM #searchTerm)
DROP TABLE #searchTerm
Try passing in the comma separated values in as a single string of nvarchar. Then use the SELECT FROM WHERE IN structure within your stored procedure. Create the sql command wwithin your stored procedure by concatenation and then call EXEC #sql
Declare #sql =
'SELECT * FROM tbl
WHERE person IN(' + #Application + ')'
exec(#sql)
Beware, if your list of search criteria is large this may not be the best solution for you.
Note that the commas should be between the full names not the first name and last name.
I need to get column names and their tables in a SQLite database. What I need is a resultset with 2 columns: table_name | column_name.
In MySQL, I'm able to get this information with a SQL query on database INFORMATION_SCHEMA. However the SQLite offers table sqlite_master:
sqlite> create table students (id INTEGER, name TEXT);
sqlite> select * from sqlite_master;
table|students|students|2|CREATE TABLE students (id INTEGER, name TEXT)
which results a DDL construction query (CREATE TABLE) which is not helpful for me and I need to parse this to get relevant information.
I need to get list of tables and join them with columns or just get columns along with table name column. So PRAGMA table_info(TABLENAME) is not working for me since I don't have table name. I want to get all column metadata in the database.
Is there a better way to get that information as a result set by querying database?
You've basically named the solution in your question.
To get a list of tables (and views), query sqlite_master as in
SELECT name, sql FROM sqlite_master
WHERE type='table'
ORDER BY name;
(see the SQLite FAQ)
To get information about the columns in a specific table, use PRAGMA table_info(table-name); as explained in the SQLite PRAGMA documentation.
I don't know of any way to get tablename|columnname returned as the result of a single query. I don't believe SQLite supports this. Your best bet is probably to use the two methods together to return the information you're looking for - first get the list of tables using sqlite_master, then loop through them to get their columns using PRAGMA table_info().
Recent versions of SQLite allow you to select against PRAGMA results now, which makes this easy:
SELECT
m.name as table_name,
p.name as column_name
FROM
sqlite_master AS m
JOIN
pragma_table_info(m.name) AS p
ORDER BY
m.name,
p.cid
where p.cid holds the column order of the CREATE TABLE statement, zero-indexed.
David Garoutte answered this here, but this SQL should execute faster, and columns are ordered by the schema, not alphabetically.
Note that table_info also contains
type (the datatype, like integer or text),
notnull (1 if the column has a NOT NULL constraint)
dflt_value (NULL if no default value)
pk (1 if the column is the table's primary key, else 0)
RTFM: https://www.sqlite.org/pragma.html#pragma_table_info
There are ".tables" and ".schema [table_name]" commands which give kind of a separated version to the result you get from "select * from sqlite_master;"
There is also "pragma table_info([table_name]);" command to get a better result for parsing instead of a construction query:
sqlite> .tables
students
sqlite> .schema students
create table students(id INTEGER, name TEXT);
sqlite> pragma table_info(students);
0|id|INTEGER|0||0
1|name|TEXT|0||0
Hope, it helps to some extent...
Another useful trick is to first get all the table names from sqlite_master.
Then for each one, fire off a query "select * from t where 1 = 0". If you analyze the structure of the resulting query - depends on what language/api you're calling it from - you get a rich structure describing the columns.
In python
c = ...db.cursor()
c.execute("select * from t where 1=0");
c.fetchall();
print c.description;
Juraj
PS. I'm in the habit of using 'where 1=0' because the record limiting syntax seems to vary from db to db. Furthermore, a good database will optimize out this always-false clause.
The same effect, in SQLite, is achieved with 'limit 0'.
FYI, if you're using .Net you can use the DbConnection.GetSchema method to retrieve information that usually is in INFORMATION_SCHEMA. If you have an abstraction layer you can have the same code for all types of databases (NOTE that MySQL seems to swich the 1st 2 arguments of the restrictions array).
Try this sqlite table schema parser, I implemented the sqlite table parser for parsing the table definitions in PHP.
It returns the full definitions (unique, primary key, type, precision, not null, references, table constraints... etc)
https://github.com/maghead/sqlite-parser
The syntax follows sqlite create table statement syntax: http://www.sqlite.org/lang_createtable.html
This is an old question but because of the number of times it has been viewed we are adding to the question for the simple reason most of the answers tell you how to find the TABLE names in the SQLite Database
WHAT DO YOU DO WHEN THE TABLE NAME IS NOT IN THE DATABASE ?
This is happening to our app because we are creating TABLES programmatically
So the code below will deal with the issue when the TABLE is NOT in or created by the Database Enjoy
public void toPageTwo(View view){
if(etQuizTable.getText().toString().equals("")){
Toast.makeText(getApplicationContext(), "Enter Table Name\n\n"
+" OR"+"\n\nMake Table First", Toast.LENGTH_LONG
).show();
etQuizTable.requestFocus();
return;
}
NEW_TABLE = etQuizTable.getText().toString().trim();
db = dbHelper.getWritableDatabase();
ArrayList<String> arrTblNames = new ArrayList<>();
Cursor c = db.rawQuery("SELECT name FROM sqlite_master WHERE
type='table'", null);
if (c.moveToFirst()) {
while ( !c.isAfterLast() ) {
arrTblNames.add( c.getString( c.getColumnIndex("name")) );
c.moveToNext();
}
}
c.close();
db.close();
boolean matchFound = false;
for(int i=0;i<arrTblNames.size();i++) {
if(arrTblNames.get(i).equals(NEW_TABLE)) {
Intent intent = new Intent(ManageTables.this, TableCreate.class
);
startActivity( intent );
matchFound = true;
}
}
if (!matchFound) {
Toast.makeText(getApplicationContext(), "No Such Table\n\n"
+" OR"+"\n\nMake Table First", Toast.LENGTH_LONG
).show();
etQuizTable.requestFocus();
}
}