I'm working on a search tool, the words (to be searched) are in object array
first i search the database(about 450k rows) using FTS4 and sqlite. This works fast, the SQL im using is:
String s = "select * from fts_sggs where word_text MATCH ? ";
but then, i need some extra words which are a part of the same table.
The FTS4 doesnt seem to work here.the sql is
String s ="select * from fts_sggs where word_number BETWEEN " + wordnumlo + " AND " + wordnumhi + " and page_number =" + pgnum;
im a newbie to SQL Programming, I need a single query that could perform both tasks fast. this is being done in java which is terribly slow.
Related
So I fetched some data from a mdb file in c# via
"SELECT * FROM " + listBox1.GetItemText(listBox1.SelectedItem) + " WHERE Note = '" + listBox2.GetItemText(listBox2.SelectedItem).Replace("'","\'") + "'";
which selects the right data, here it is
SELECT * FROM Main WHERE Note ='Hello'
The mdb data structure looks like this being plotted as a CSV-file:
"Record ID";Status;Placement;Private;Category;Note;Blob
14341665;4;2147483647;True;3;"""Hello"" - Neues
But when I try to remove entries with
"DELETE FROM " + listBox1.GetItemText(listBox1.SelectedItem) + " WHERE \"Record ID\" LIKE '" + dr[0] + "';";
or
"DELETE FROM " + listBox1.GetItemText(listBox1.SelectedItem) + " WHERE \"Record ID\" = '" + dr[0] + "';";
which looks like for instance
DELETE FROM Main WHERE "Record ID" LIKE '14341665';
The entries just stay there. I can rerun the select command even restart my application, the mdb is not changed.
Is record ID a numeric field? If so, lose the quotes.
DELETE FROM Main WHERE [Record ID] = 14341665;
Note that spaces in field (column) names will always be a problem. Such columns names have to be enclosed in square brackets, as do columns named with reserved words.
The record id is numeric, so don't put apostrophes around it:
"DELETE FROM " + listBox1.GetItemText(listBox1.SelectedItem) + " WHERE \"Record ID\" = " + dr[0]
Note: You should avoid using select * in production code, you should specify the data that you want returned. Also, you should use parameterised queries instead of concatenating values into the query.
if i remember correctly, "like" only works on string data, please check the data type of Record ID.
If Record ID is numeric, you may want to use database's conversion function to convert it into string before filtering using "like".
btw, remember to make sure that dr[0] is properly escaped.
SAMPLE CODE:
Dim sql As String = "SELECT * FROM " + tblName + " WHERE needsTranslation = 'True' AND dataText LIKE " & "'" & alpha & "%" & "'" & " ORDER BY dataText;"
da = New SqlDataAdapter(sql, strConnection)
OP:
I would like to create a SQL query that returns all records when the first letter of a string matches my variable. I am coding this in an ASP.net code behind page in vb.net.
SELECT * FROM " + tblName + " WHERE textData = ' & alpha & "
In this exmample textData is a string of text and alpha is a single letter a through z or A through Z.
I don't need the criteria to be case sensitive, but I do need only the first letter of textData to match alpha.
I have tested the LIKE comparator and it does not return all records that begin with alpha.
What is the best way to do this? Any and all help will be appreciated.
thanks again,
The LIKE operator is what you'd want to use, but you have to use the % wildcard character like so:
SELECT * FROM MyTable WHERE textData LIKE 'a%'
SQL has sub-string operator SUBSTR() or SUBSTRING()
select * from tableName where substr( textData ) in ( 'A', 'B', 'C', ... );
I couldn't add to the comments on one of the other posts, but I'll strongly second the need to use a parameterized query for these reasons (you can include usage of the like operator with the wildcard % like the other answer correctly summarized to answer your question):
It will protect you from making mistakes with single quotes, especially if the user enters a search string that includes them
(they will cause your query to fail).
It protects you from SQL injection exploits. Example, a user were able to input the value of the variable "alpha" in the above
example they could enter something like:
'; DELETE FROM ;
If the user you were using had excessive database rights, they could
wreak all kinds of havoc (or they could potentially get access to
data they shouldn't have access to).
So I've recently been working on a VBA script to transfer an entire database of student medical records from their old one-table, 68-field, flat system to a new dynamic system with 24 related tables.
There was no issue for the first few tables, but then I ran into this. The line of code throwing the error is:
Set rstFrom = CurrentDb.OpenRecordset("select " & Flat & ".Student," & Flat & ".School," & Flat & ".Social," & Flat & ".FamilyHist from " & Flat & " WHERE 1=1")`
Flat is a String which stores the name of the flat database (this is because I'm working with a dummy database so they will need a convenient and quick way to modify the code I make to work on the real thing)
rstFrom needs to contain only the columns of the 68-field table which are relevant to the table that I'm copying to at the moment (in this case, the FamilyHistory table which really just needs the studentID and FamilyHistory) - note that the original table did not assign unique studentIDs, so I must use the name, school, and social to determine that I am dealing with the same child and look up their studentID
When this line of code runs I get the following error:
Run-time error '3061':
Too few parameters. Expected 1.
Clearly I have 1 parameter, it's:
"select " & Flat & ".Student," & Flat & ".School," & Flat & ".Social," & Flat & ".FamilyHist from " & Flat & " WHERE 1=1"
(which after parsing is):
"select Demos.Student,Demos.School,Demos.Social,Demos.FamilyHist from Demos WHERE 1=1"
The where 1=1 is required when working with Access VBA or else it only returns the first record which matches, not all matching records.
Has anyone else had this same problem as resolved it? I did notice one thing. When I change the parameter to:
"select Demos.Student from Demos WHERE 1=1"
It is able to get past this line no problem, although this causes issues later on when I need to read other data that I did not retrieve. I thought it was interesting, though, that the error seems to be coming from the SQL and not the OpenRecordset function.
Check the field names in the SQL vs what you have in table.
I think, either the field name in above SQL is misspell or you don't have one or more field (of SQL statement) in the table.
The text parameters in the insert query need to have a single quote around them. I ran into the same problem with a query using Visual C++.
Here's the code I ended up using...
void FileInterface::TblWrite(CDatabase* db, rec* r)
{
string sqlQuery = "insert into THREATS(ID,CODE,ID,LAT,LON,SHOW_A,SHOW_B) Values(" +
to_string((_Longlong)r->num) + "," +
to_string((_Longlong)r->code) + "," +
"'" + r->id + "'" + "," +
to_string((long double)r->lat) + "," +
to_string((long double)r->lon) + "," +
"1" + "," +
"1" +
")";
db->ExecuteSQL(sqlQuery.c_str());
}
How can I convert the following SQL query into HQL?
SELECT count(sa.AID)
FROM A sa
, B sal,C m
WHERE sa.AID = sal.AID(+) and sa.BID = m.BID and sa.AID ='0001'
You need to transfer each table/column into it's associated Entity/Class in JAVA, then build the query with Hibernate ORM as below.
Suppose
- The entity name for the table sa is saEntity, for the table B is bEntity, and for the table C is cEntity.
- The class name for the column AID is AidClass, and for the column BID is BidClass
Then the Hibernate ORM query can be written as per the following (I like formating HQL queries inside annotations on multiple lines to make it easier to read & adapt).
#Query( "SELECT COUNT(sa.AidClass) "
+ "FROM saEntity sa, "
+ " bEntity sal "
+ " cEntity m"
+ "WHERE sa.AidClass = sal.AidClass"
+ " AND sa.BidClass = m.BidClass "
+ " AND sa.AidClass ='0001'")
public List <?> runMyQueryMethod();
Try looking at the answer to this question.
HQL to SQL converter
Or this article may help..
https://forum.hibernate.org/viewtopic.php?t=972441
If you showed some of the mappings I could probably help with the HQL. You could just use
Session.CreateSQLQuery instead??
I'm using VBA excel 2003,SQL 2005 to make a sql query call and inside my sql statement I'm using '+' operator to concatenate two strings.
dim query as string
query = "Select distinct ', '+emailaddress1 "
query = query & "from contact "
would this work inside vba? My query returns too many records in excel but not in SQL?
Please just focus on this 2 lines of code and not worry about the rest of my sql call, I'm just wondering whether or not this specific string would work?
Your code will return a column where each row would be an email address with a comma in front of it. If that is what you want, then yes, it will work.
If, on contrary, you want a single string where all email addresses would be listed, separated with commas, that'd be
query = "declare #foo varchar(max);"
query = query & "select distinct #foo = isnull(#foo,'') + emailaddress1 + ', ' from contact;"
query = query & "select left(#foo, len(#foo)-2);"