I am trying to add CHECK constraints for my table in database, but I am getting error CHECK Constraint failed everytime I tried adding values in table. It may syntax error for SQLite. Thanks in advance.
CREATE TABLE `staff` (
`sid` INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT UNIQUE,
`sname` TEXT NOT NULL,
`semail` TEXT NOT NULL UNIQUE,
`sphone` TEXT NOT NULL CHECK(length ( 'sphone' ) = 10) UNIQUE,
`sdept` TEXT NOT NULL CHECK(length ( 'sdept ' ) = 2),
`spassword` TEXT NOT NULL CHECK(length ( 'spassword' ) <= 8));
You shouldn't have single quotes around your column names in the constraint clauses; that turns the names into strings. You should replace the single-quotes with double quotes or omit them altogether. (You should also replace the back-quotes in your table and column names with either double-quotes or nothing at all to conform to the SQL standard.)
Related
output--
I have written the query in snowflake to generate Json file, from the query output want to remove fields which has NULL. OBJECT_CONSTRUCT is not working properly for some column its not passing NULL value where else for some column its giving null value as result.
Input-
Json remove any field which has value NULL or blank.
{"DIFID":122,"DIF_FLAG":"NULL","DIF_TYPE":"asian/white","FOCAL_COUNT":2370,"REFERENCE_COUNT":17304},
Required Output-
Json remove any field which has value NULL or blank.
{"DIFID":122,"DIF_TYPE":"asian/white","FOCAL_COUNT":2370,"REFERENCE_COUNT":17304},
query-
select distinct ITEMSTATID,object_construct(
'DIFID',DIFID,
'DIF_TYPE',DIF_TYPE,
'DIF_FLAG',DIF_FLAG,
'FOCAL_COUNT',FOCAL_COUNT::integer,
'REFERENCE_COUNT',REFERENCE_COUNT::integer,
'DIF_METHOD',DIF_METHOD,
'DIF_VALUE',DIF_VALUE)
DIF
from DEV_IPM.STAGEVAULT.DIF_STATISTICS;
For string column and 'NULL' as string literal column's value is not skipped:
CREATE OR REPLACE TABLE DIF_STATISTICS
AS
SELECT 1 AS ITEMSTATID,
122 AS DIFID,
'NULL' AS DIF_FLAG, -- here
'asian/white' AS DIF_TYPE,
2370 AS FOCAL_COUNT,
17304 AS REFERENCE_COUNT;
Output:
The value is definitely stored as TEXT:
SELECT null AS DIF_FLAG, 'NULL' AS DIF_FLAG;
On the left: true NULL on the right: NULL string
If it the case then it should be nullified NULLIF(DIF_FLAG, 'NULL') before passing to OBJECT_CONSTRUCT function:
SELECT ITEMSTATID,
object_construct(
'DIFID',DIFID,
'DIF_TYPE',DIF_TYPE,
'DIF_FLAG',NULLIF(DIF_FLAG, 'NULL'),
'FOCAL_COUNT',FOCAL_COUNT::integer,
'REFERENCE_COUNT',REFERENCE_COUNT::integer) AS DIF
FROM DIF_STATISTICS;
Previous answer before column details were provided (also plausible):
It is working as intended:
NULL Values
Snowflake supports two types of NULL values in semi-structured data:
SQL NULL: SQL NULL means the same thing for semi-structured data types as it means for structured data types: the value is missing or unknown.
JSON null (sometimes called “VARIANT NULL”): In a VARIANT column, JSON null values are stored as a string containing the word “null” to distinguish them from SQL NULL values.
OBJECT_CONSTRUCT
If the key or value is NULL (i.e. SQL NULL), the key-value pair is omitted from the resulting object. A key-value pair consisting of a not-null string as key and a JSON NULL as value (i.e. PARSE_JSON(‘NULL’)) is not omitted.
For true SQL NULL values, that column is ommitted:
CREATE OR REPLACE TABLE DIF_STATISTICS
AS
SELECT 1 AS ITEMSTATID,
122 AS DIFID,
NULL AS DIF_FLAG,
'asian/white' AS DIF_TYPE,
2370 AS FOCAL_COUNT,
17304 AS REFERENCE_COUNT;
SELECT ITEMSTATID,
object_construct(
'DIFID',DIFID,
'DIF_TYPE',DIF_TYPE,
'DIF_FLAG',DIF_FLAG,
'FOCAL_COUNT',FOCAL_COUNT::integer,
'REFERENCE_COUNT',REFERENCE_COUNT::integer) AS DIF
FROM DIF_STATISTICS;
Output:
Probably the data type of the column DIFID is VARIANT/OBJECT:
CREATE OR REPLACE TABLE DIF_STATISTICS
AS
SELECT 1 AS ITEMSTATID,
122 AS DIFID,
PARSE_JSON('NULL') AS DIF_FLAG, -- here
'asian/white' AS DIF_TYPE,
2370 AS FOCAL_COUNT,
17304 AS REFERENCE_COUNT;
Output:
I am new to Dapper, want to know why below is suggested, when my code runs without it?
Ansi Strings and varchar
Dapper supports varchar params, if you are executing a where clause on
a varchar column using a param be sure to pass it in this way:
Query<Thing>("select * from Thing where Name = #Name", new {Name = new
DbString { Value = "abcde", IsFixedLength = true, Length = 10, IsAnsi
= true });
On SQL Server it is crucial to use the unicode when querying unicode
and ansi when querying non unicode.
Below is my code, which runs against SQL server 2012 without using DbString etc.
create table Author (
Id int identity(1,1),
FirstName varchar(50),
LastName varchar(50)
);
go
insert into Author (FirstName, LastName) values ('Tom', 'John');
public Author FindByVarchar(string firstName)
{
using (IDbConnection db = DBHelper.NewSqlConnection())
{
return db.Query<Author>("Select * From Author WHERE FirstName = #firstName", new { firstName }).SingleOrDefault();
}
}
Questions:
1 Why is DbString type used in this case?
2 Why the length is set to 10 (e.g.Length = 10) when "abcde" is 5?
3 Do I still need to use DbString when my current code works?
4 Is it correct to set IsAnsi = false for unicode column?
5 For varchar column, is it correct to set IsFixedLength = false, and ignore setting Length?
The purpose of the example is that it is describing a scenario where the data type is char(10). If we just used "abcde", Dapper might think that nvarchar(5) was appropriate. This would be very inefficient in some cases - especially in a where clause, since the RDBMS can decide that it can't use the index, and instead needs to table scan doing a string conversion for every row in the table from char(10) to the nvarchar version. It is for this reason that DbString exists - to help you control exactly how Dapper configures the parameter for text data.
I think this answers your 1 and 2.
3: are you using ANSI (non-unicode text) or fixed-width text? Note that the ANSI default can also be set globally if you always avoid unicode
4: yes
5: yes
4+5 combined: if you're using nvarchar: just use string
I have the following table (maximum number of records 999) I use for a lookup:
CREATE TABLE lga
(
lgacode character varying(3) NOT NULL DEFAULT '000'::character varying,
lganame character varying(32) NOT NULL,
CONSTRAINT pk_lga PRIMARY KEY (lganame),
CONSTRAINT uk_lga UNIQUE (lgacode)
);
Using Anorm, I easily get a result list lgas of the type List[models.LgaTable]
How do I get this result list into the form List[Tuple2[String,String]]?
I searched Stack Overflow and found something close ([a link]http://stackoverflow.com/questions/4927260/filling-a-scala-immutable-map-from-a-database-table) but this contained Set, which I have an aversion for, meanwhile: I just needed something simple. Thanks
Just call a map on your result:
val lgas: List[models.LgaTable] = ...
val lgas_tupled = lags.map(row => (row.lgacode, lganame))
Does a unique constraint include a not null constraint?
I have a case that one attribute cellPhone can be NULL but cannot be repeated, so I give it 2 constraints: "not null" and "unique", in a case of updating the record, if user didn't enter a value I put 0 in the field, so it makes this exception:
SEVERE: java.sql.SQLIntegrityConstraintViolationException: ORA-00001: unique constraint (TEST1.OSQS_PARENTS_CELLPHONE_UK) violated
What should I do in the UPDATE case?
EDIT
here's the definition of table ddl
CREATE TABLE "TEST1"."OSQS_PARENTS"
( "PARENT_NO" NUMBER(38,0),
"PARENT_NAME" VARCHAR2(4000 BYTE),
"PARENT_ID" NUMBER(38,0),
"PARENT_EMAIL" VARCHAR2(30 BYTE),
"PARENT_CELLPHONE" NUMBER(38,0)
)
and here's an image of the constraints
and here is the update statement
Parent aParent; //is an object I pass through a function
String SQlUpdate = "UPDATE OSQS_PARENTS P SET P.PARENT_ID=?,P.PARENT_EMAIL=?,P.PARENT_CELLPHONE=?"
+ " where P.PARENT_NO=?";
PreparedStatement pstmt = null;
try {
pstmt = con.prepareStatement(SQlUpdate);
pstmt.setLong(1, aParent.getId());
pstmt.setString(2, aParent.getEmail());
pstmt.setLong(3, aParent.getCellPhoneNo());
pstmt.setLong(4, parentNo);
pstmt.executeUpdate();
}
it sounds like this:
cellPhone must be unique. When user does not input value, you mark it as a 0. Thus it fails when you try to insert multiple 0 values into a 'UNIQUE' column.
I believe you need to drop the NOT NULL constraint on the column (allow it to be UNIQUE yes, but allow NULLS).
Then when user inputs no value, use it as a NO value (unknown = null <> 0 -- 0 is a known value )
throw an IF into your statement, if value then what you have, otherwise SET IT TO NULL!\
pstmt.setNull(3, java.sql.Types.INTEGER);
I have some filters in the following form:
Object A
+/- Start End
----------------------------------------------
+ 000000080000 000000090000
- 000000800500
+ 054*
Object B
+/- Start End
----------------------------------------------
+ 000000090000 000000100000
+ 00??00900500
- 000000900500
+ 055*
It means:
Numbers between 000000080000 and 000000090000 except 000000800500, and numbers starting with 054 are associated with object A.
Numbers between 000000090000 and 000000100000 except 000000900500, numbers matching 00??00900500 (except 000000900500 of course), and numbers starting with 055 are associated with object B.
Example of the table structure:
CREATE TABLE dbo.Filter
(
IDFilter int IDENTITY PRIMARY KEY
)
CREATE TABLE dbo.FilterRow
(
IDFilterRow int IDENTITY PRIMARY KEY
,IDFilter int FOREIGN KEY REFERENCES dbo.Filter(IDFilter) NOT NULL
,Operator bit --0 = -, 1 = + NOT NULL
,StartNumber varchar(50) NOT NULL
,EndNumber varchar(50)
)
CREATE TABLE dbo.[Object]
(
IDObject int IDENTITY PRIMARY KEY
,Name varchar(10) NOT NULL
,IDFilter int FOREIGN KEY REFERENCES dbo.Filter(IDFilter) NOT NULL
)
I need a way to make sure no numbers can get associated with more than 1 object, in SQL (or CLR), and I really have no clue how to do such a thing (besides bruteforce).
I do have a CLR function Utils.fIsInFilter('?8*', '181235467895') that supports wildcards and would return 1, if it helps...
Can you use a CLR function in SQL 2005?
It's possible in raw SQL using LIKE JOINS (where ? becomes [0-9] and * becomes %), perhaps followed by CAST, but this is what CLR functions are for...