Assuming that all values of MBR_DTH_DT evaluate to a Date data type other than the value '00000000', could the following UPDATE SQL fail when running on multiple processors if the CAST were performed before the filter by racing threads?
UPDATE a
SET a.[MBR_DTH_DT] = cast(a.[MBR_DTH_DT] as date)
FROM [IPDP_MEMBER_DEMOGRAPHIC_DECBR] a
WHERE a.[MBR_DTH_DT] <> '00000000'
I am trying to find the source of the following error
Error: 2014-01-30 04:42:47.67
Code: 0xC002F210
Source: Execute csp_load_ipdp_member_demographic Execute SQL Task
Description: Executing the query "exec dbo.csp_load_ipdp_member_demographic" failed with the following error: "Conversion failed when converting date and/or time from character string.". Possible failure reasons: Problems with the query, "ResultSet" property not set correctly, parameters not set correctly, or connection not established correctly.
End Error
It could be another UPDATE or INSERT query, but the otehrs in question appear to have data that is proeprly typed from what I see,, so I am left onbly with the above.
No, it simply sounds like you have bad data in the MBR_DTH_DT column, which is VARCHAR but should be a date (once you clean out the bad data).
You can identify those rows using:
SELECT MBR_DTH_DT
FROM dbo.IPDP_MEMBER_DEMOGRAPHIC_DECBR
WHERE ISDATE(MBR_DTH_DT) = 0;
Now, you may only get rows that happen to match the where clause you're using to filter (e.g. MBR_DTH_DT = '00000000').
This has nothing to do with multiple processors, race conditions, etc. It's just that SQL Server can try to perform the cast before it applies the filter.
Randy suggests adding an additional clause, but this is not enough, because the CAST can still happen before any/all filters. You usually work around this by something like this (though it makes absolutely no sense in your case, when everything is the same column):
UPDATE dbo.IPDP_MEMBER_DEMOGRAPHIC_DECBR
SET MBR_DTH_DT = CASE
WHEN ISDATE(MBR_DTH_DT) = 1 THEN CAST(MBR_DTH_DT AS DATE)
ELSE MBR_DTH_DT END
WHERE MBR_DTH_DT <> '00000000';
(I'm not sure why in the question you're using UPDATE alias FROM table AS alias syntax; with a single-table update, this only serves to make the syntax more convoluted.)
However, in this case, this does you absolutely no good; since the target column is a string, you're just trying to convert a string to a date and back to a string again.
The real solution: stop using strings to store dates, and stop using token strings like '00000000' to denote that a date isn't available. Either use a dimension table for your dates or just live with NULL already.
Not likely. Even with multiple processors, there is no guarantee the query will processed in parallel.
Why not try something like this, assuming you're using SQL Server 2012. Even if you're not, you could write a UDF to validate a date like this.
UPDATE a
SET a.[MBR_DTH_DT] = cast(a.[MBR_DTH_DT] as date)
FROM [IPDP_MEMBER_DEMOGRAPHIC_DECBR] a
WHERE a.[MBR_DTH_DT] <> '00000000' And IsDate(MBR_DTH_DT) = 1
Most likely you have bad data are are not aware of it.
Whoops, just checked. IsDate has been available since SQL 2005. So try using it.
This query works fine in the query window of SQL Server 2005, but throws error when I run it in Execute SQL Task in the ssis package.
declare #VarExpiredDays int
Select #VarExpiredDays= Value1 From dbo.Configuration(nolock) where Type=11
DECLARE #VarENDDateTime datetime,#VarStartDateTime datetime
SET #VarStartDateTime= GETDATE()- #VarExpiredDays
SET #VarENDDateTime=GETDATE();
select #VarStartDateTime
select #VarENDDateTime
SELECT * FROM
(SELECT CONVERT(Varchar(11),#VarStartDateTime,106) AS VarStartDateTime) A,
(SELECT CONVERT(Varchar(11),#VarENDDateTime,106) AS VarENDDateTime) B
What is the issue here?
Your intention is to retrieve the values of start and end and assign those into SSIS variables.
As #Diego noted above, those two SELECTS are going to cause trouble. With the Execute SQL task, your resultset options are None, Single Row, Full resultset and XML. Discarding the XML option because I don't want to deal with it and None because we want rows back, our options are Single or Full. We could use Full, but then we'd need to return values of the same data type and then the processing gets much more complicated.
By process of elimination, that leads us to using a resultset of Single Row.
Query aka SQLStatement
I corrected the supplied query by simply removing the two aforementioned SELECTS. The final select can be simplified to the following (no need to put them into derived tables)
SELECT
CONVERT(Varchar(11),#VarStartDateTime,106) AS VarStartDateTime
, CONVERT(Varchar(11),#VarENDDateTime,106) AS VarENDDateTime
Full query used below
declare #VarExpiredDays int
-- I HARDCODED THIS
Select #VarExpiredDays= 10
DECLARE #VarENDDateTime datetime,#VarStartDateTime datetime
SET #VarStartDateTime= GETDATE()- #VarExpiredDays
SET #VarENDDateTime=GETDATE();
/*
select #VarStartDateTime
select #VarENDDateTime
*/
SELECT * FROM
(SELECT CONVERT(Varchar(11),#VarStartDateTime,106) AS VarStartDateTime) A,
(SELECT CONVERT(Varchar(11),#VarENDDateTime,106) AS VarENDDateTime) B
Verify the Execute SQL Task runs as expected. At this point, it simply becomes a matter of wiring up the outputs to SSIS variables. As you can see in the results window below, I created two package level variables StartDateText and EndDateText of type String with default values of an empty string. You can see in the Locals window they have values assigned that correspond to #VarExpiredDays = 10 in the supplied source query
Getting there is simply a matter of configuring the Result Set tab of the Execute SQL Task. The hardest part of this is ensuring you have a correct mapping between source system type and SSIS type. With an OLE DB connection, the Result Name has no bearing on what the column is called in the query. It is simply a matter of referencing columns by their ordinal position (0 based counting).
Final thought, I find it better to keep things in their base type, like a datetime data type and let the interface format it into a pretty, localized value.
you have more that one output type. You have two variables and one query.
You need to select only one on the "resultset" propertie
are you mapping these to the output parameters?
select #VarStartDateTime
select #VarENDDateTime
I am trying to learn how to do radius search on records using the new SqlServer 2008 managed spacial type and methods (geography) for doing geospatial calculations. I am following the samples on this web page:
http://msdn.microsoft.com/en-us/magazine/dd434647.aspx
I am specifically trying to do this sample:
-- or declare POINT for "downtown Seattle"
-- 1609.344 meters per mile
DECLARE #Seattle geography = 'POLYGON(....)'; SELECT c.customerid FROM
customer c WHERE c.geog.STIntersects(#Seattle.STBuffer(10 * 1609.344));
However, even before running the query (or when I run the quer--both compile and runtime error)I am getting the following error message:
An expression of non-boolean type specified in a context where a condition is expected, near ')'
I am really baffled by this. I am not doing exactly the same query (I am using my own data with a geography column) but it is almost identical to the sample. I am running Sql SErver 2008 SP2 Standard Edition 64-bit. When I type the query it uses intellisense for the STIntersection method and shows a (other_geography geography) sample so it knows that the method exists. I am properly closing the parentheses and delimiting the expression with a semi-colon but I cannot figure out why I am getting the error. Googling has not worked.
Any thoughts?
Seth
STIntersects returns 0 or 1. Try this:
WHERE c.geog.STIntersects(#Seattle.STBuffer(10 * 1609.344)) = 1
I just asked an SQL related question, and the first answer was: "This is a situation where dynamic SQL is the way to go."
As I had never heard of dynamic SQL before, I immediately searched this site and the web for what it was. Wikipedia has no article with this title. The first Google results all point to user forums where people ask more or less related questions.
However, I didn't find a clear definition of what a 'dynamic SQL' is. Is it something vendor specific? I work with MySQL and I didn't find a reference in the MySQL handbook (only questions, mostly unanswered, in the MySQL user forums).
On the other hand, I found many references to stored procedures. I have a slightly better grasp of what stored procedures are, although I have never used any. How are the two concepts related? Are they the same thing or does one uses the other?
Basically, what is needed is a simple introduction to dynamic SQL for someone who is new to the concept.
P.S.: If you feel like it, you may have a go at answering my previous question that prompted this one: SQL: How can we make a table1 JOIN table2 ON a table given in a field in table1?
Dynamic SQL is merely where the query has been built on the fly - with some vendors, you can build up the text of the dynamic query within one stored procedure, and then execute the generated SQL. In other cases, the term merely refers to a decision made by code on the client (this is at least vendor neutral)
Other answers have defined what dynamic SQL is, but I didn't see any other answers that attempted to describe why we sometimes need to use it. (My experience is SQL Server, but I think other products are generally similar in this respect.)
Dynamic SQL is useful when you are replacing parts of a query that can't be replaced using other methods.
For example, every time you call a query like:
SELECT OrderID, OrderDate, TotalPrice FROM Orders WHERE CustomerID = ??
you will be passing in a different value for CustomerID. This is the simplest case, and one that can by solved using a parameterized query, or a stored procedure that accepts a parameter, etc.
Generally speaking, dynamic SQL should be avoided in favor of parameterized queries, for performance and security reasons. (Although the performance difference probably varies quite a bit between vendors, and perhaps even between product versions, or even server configuration).
Other queries are possible to do using parameters, but might be simpler as dynamic SQL:
SELECT OrderID, OrderDate, TotalPrice FROM Orders
WHERE CustomerID IN (??,??,??)
If you always had 3 values, this is as easy as the first one. But what if this is a variable-length list? Its possible to do with parameters, but can be very difficult. How about:
SELECT OrderID, OrderDate, TotalPrice FROM Orders WHERE CustomerID = ??
ORDER BY ??
This can't be substituted directly, you can do it with a huge complicated CASE statement in the ORDER BY explicitly listing all possible fields, which may or may not be practical, depending on the number of fields available to sort by.
Finally, some queries simply CAN'T be done using any other method.
Let's say you have a bunch of Orders tables (not saying this is great design), but you might find yourself hoping you can do something like:
SELECT OrderID, OrderDate, TotalPrice FROM ?? WHERE CustomerID = ??
This can't be done using any other methods. In my environment, I frequently encounter queries like:
SELECT (programatically built list of fields)
FROM table1 INNER JOIN table2
(Optional INNER JOIN to table3)
WHERE (condition1)
AND (long list of other optional WHERE clauses)
Again, not saying that this is necessarily great design, but dynamic SQL is pretty much required for these types of queries.
Hope this helps.
Dynamic SQL is simply a SQL statement that is composed on the fly before being executed. For example, the following C# (using a parameterized query):
var command = new SqlCommand("select * from myTable where id = #someId");
command.Parameters.Add(new SqlParameter("#someId", idValue));
Could be re-written using dynamic sql as:
var command = new SqlCommand("select * from myTable where id = " + idValue);
Keep in mind, though, that Dynamic SQL is dangerous since it readily allows for SQL Injection attacks.
Dynamic SQL is a SQL built from strings at runtime. It is useful to dynamically set filters or other stuff.
An example:
declare #sql_clause varchar(1000)
declare #sql varchar(5000)
set #sql_clause = ' and '
set #sql = ' insert into #tmp
select
*
from Table
where propA = 1 '
if #param1 <> ''
begin
set #sql = #sql + #sql_clause + ' prop1 in (' + #param1 + ')'
end
if #param2 <> ''
begin
set #sql = #sql + #sql_clause + ' prop2 in (' + #param2 + ')'
end
exec(#sql)
It is exactly what Rowland mentioned. To elaborate on that a bit, take the following SQL:
Select * from table1 where id = 1
I am not sure which language you are using to connect to the database, but if I were to use C#, an example of a dynamic SQL query would be something like this:
string sqlCmd = "Select * from table1 where id = " + userid;
You want to avoid using dynamic SQL, because it becomes a bit cumbersome to keep integrity of the code if the query get too big. Also, very important, dynamic SQL is susceptible to SQL injection attacks.
A better way of writing the above statement would be to use parameters, if you are using SQL Server.
Rowland is correct, and as an addendum, unless you're properly using parameters (versus just concatonating parameter values inline from provided text, etc.) it can also be a security risk. It's also a bear to debug, etc.
Lastly, whenever you use dynamic SQL unwisely, things are unleashed and children are eaten.
To most databases, every SQL query is "dynamic" meaning that it is a program that is interpreted by the query optimiser given the input SQL string and possibly the parameter bindings ("bind variables").
Static SQL
However, most of the time, that SQL string is not constructed dynamically but statically, either in procedural languages like PL/SQL:
FOR rec IN (SELECT * FROM foo WHERE x = 1) LOOP
-- ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ "static SQL"
..
END LOOP;
Or in client / host languages like Java, using JDBC:
try (ResultSet rs = stmt.executeQuery("SELECT * FROM foo WHERE x = 1")) {
// "static SQL" ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
..
}
In both cases, the SQL string is "static" in the language that embeds it. Technically, it will still be "dynamic" to the SQL engine, which doesn't know how the SQL string is constructed, nor that it was a static SQL string.
Dynamic SQL
Sometimes, the SQL string needs to be constructed dynamically, given some input parameters. E.g. the above query might not need any predicate at all in some cases.
You might then choose to proceed to constructing the string dynamically, e.g. in PL/SQL:
DECLARE
TYPE foo_c IS REF CURSOR;
v_foo_c foo_c;
v_foo foo%ROWTYPE;
sql VARCHAR2(1000);
BEGIN
sql := 'SELECT * FROM foo';
IF something THEN
sql := sql || ' WHERE x = 1'; -- Beware of syntax errors and SQL injection!
END IF;
OPEN v_foo_c FOR sql;
LOOP
FETCH v_foo_c INTO v_foo;
EXIT WHEN v_foo_c%NOTFOUND;
END LOOP;
END;
Or in Java / JDBC:
String sql = "SELECT * FROM foo";
if (something)
sql += " WHERE x = 1"; // Beware of syntax errors and SQL injection!
try (ResultSet rs = stmt.executeQuery(sql)) {
..
}
Or in Java using a SQL builder like jOOQ
// No syntax error / SQL injection risk here
Condition condition = something ? FOO.X.eq(1) : DSL.trueCondition();
for (FooRecord foo : DSL.using(configuration)
.selectFrom(FOO)
.where(condition)) {
..
}
Many languages have query builder libraries like the above, which shine most when doing dynamic SQL.
(Disclaimer: I work for the company behind jOOQ)
Is it something vendor specific?
The SQL-92 Standard has a whole chapter on dynamic SQL (chapter 17) but it only applies to FULL SQL-92 and I know of no vendor that has implemented it.
I think what's meant is that you should build the query dynamically before executing it. For your other questions this means that you should select the table name you need first and the use your programming language to build a second query for doing what you want (what you want to do in the other question isn't possible directly like you want).
Is there any way to directly access the stemmer used in the FORMSOF() option of a CONTAINS Full Text Search query so that it returns the stems/inflections of an input word, not just those derivations that exist in a search column.
For example, the query
SELECT * FROM dbo.MyDB WHERE contains(CHAR_COL,'FORMSOF(INFLECTIONAL, prettier)')
returns the stem "pretty" and other inflections such as "prettiest" if they exists in the CHAR_COL column. What I want is to call the FORMSOF() function directly without referencing a column at all. Any chance?
EDIT:
The query that met my needs ended up being
SELECT * FROM
(SELECT ROW_NUMBER() OVER (PARTITION BY group_ID ORDER BY GROUP_ID) ord, display_term
from sys.dm_fts_parser('FORMSOF( FREETEXT, running) and FORMSOF(FREETEXT, jumping)', 1033, null, 1)) a
WHERE ord=1
Requires membership in the sysadmin
fixed server role and access rights to
the specified stoplist.
No. You can not do this. You can't get an access to stemmer directly.
You can get an idea of how it works by looking into Solr source code. But it might (and I guess will) be different from the one implemented in MS SQL FT.
UPDATE: It turns out that in SQL Server 2008 R2 you can do something quite close to what you want. A special table-valued UDF was added:
sys.dm_fts_parser('query_string', lcid, stoplist_id, accent_sensitivity)
it allows you to get a tokenization result (i.e. the result after applying word breaking, thesaurus and stop list application). So in case you feed it 'FORMSOF(....)' it will give you the result you want (well, you will have to process result set anyway). Here's corresponding article in MSDN.