Specifies the type of data being stored (string, date, numeric, etc).

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1
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1answer
682 views

MongoDB Keys and casting between types

This is more of a theoretical question: Let's say I have a collection of documents, my_collection: { "_id": ObjectId("52c679ac7a23e6225b62c51f"), "date": ISODate("2014-01-06T03:48:30.737Z") ...
4
votes
2answers
3k views

What is the meaning of tinyint(N)?

When we use an argument length with numerical data types, as far as I know this specifies the display width. I tried the following: mysql> create table boolean_test (var1 boolean, var2 tinyint); ...
0
votes
1answer
522 views

Datetime Difference in MySQL when format is Varchar

I have two columns in a table: STOP and START, of type varchar. I want to have the difference between both columns, and I'm using : SELECT DATEDIFF(stop, start) AS difference from T1; It is ...
2
votes
2answers
117 views

Is this an example of an Enum (Enumerated Type)

I'm looking at a code base that I have inherited. I'm new to Postgres (but have an Oracle background), and I think this in one of the queries is an example of an enum. Can someone confirm if I'm ...
3
votes
1answer
2k views

Why aren't unsigned integer types available in the top database platforms?

Databases are usually very customizable with varying data types and custom lengths. It surprises me, as I try to look for the syntax to use unsigned int types that they are not available from neither ...
0
votes
1answer
725 views

Oracle - how to reference to a field%TYPE using database links?

I have this database which includes a couple of schemas. Say I need to access schemaONE from schemaTWO. To do this, I have created a database link named "DB_ONE_LINK". I am able to access to ...
1
vote
1answer
243 views

PostgreSQL 9.2 number of days in a tstzrange?

How can the number of days contained within a range be found? For example, with these timestamp ranges, get these (integer) number of days: tstzrange('2013-10-01 07:00', '2013-10-01 07:15') | 1 ...
3
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1answer
1k views

Datatype bigger than bigint

I want to use dataype which can hold more than 19 digits. So is there any datatype available which can hold larger than 19 digits?
8
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2answers
9k views

How to combine date and time to datetime2 in SQL Server?

Given the following components DECLARE @D DATE = '2013-10-13' DECLARE @T TIME(7) = '23:59:59.9999999' What is the best way of combining them to produce a DATETIME2(7) result with value '2013-10-13 ...
1
vote
2answers
245 views

Help me to map Column types betwenn SQL and TopSpeed Clarion Tables

I am tasked to convert an old Clarion App to new one under SQL Server 2012. All I have is 200 tables with TPS extension which I can open only by program called TopScan. (No odbc, no technical ...
2
votes
1answer
5k views

Changing a column data type from datetime to float

I have a table with a float column. All values in this column for all records are NULL. I want to change the data type to datetime. I executed the query: ALTER TABLE MyTable ALTER Column MyColumn ...
4
votes
1answer
374 views

Understanding MS SQL Server Date Types

Consider the following: declare @dt datetime, @dt2 datetime2, @d date set @dt = '2013-01-01' set @dt2 = '2013-01-01' set @d = '2013-01-01' select convert(varbinary, @dt) as dt, ...
-1
votes
1answer
237 views

Recommended datatype fixed length in mysql

What's the best data type for store fix length data such as MD5 password 1f3870be274f6c49b3e31a0c6728957f HEX Ccolor f2a709 They don't need character sets. All in absolute [a-z0-9]{6} for color, ...
1
vote
2answers
787 views

boolean purpose column char(0) or tinyint(1)

For Boolean purpose column which one is better: nullable char(0) or tinyint(1). I know bool is an alias for tinyint(1) , but in "High Performance MySQL" book that published by O'reilly said: "If ...
1
vote
1answer
286 views

Column of generic/variable type?

In SQL, I would like to create a table which can contain generic data types. This types can change from every row. The solution I could come up to is: CREATE TABLE TagValue ( tag VARCHAR(64), ...
0
votes
2answers
209 views

Should numeric identifiers like serial numbers be stored as integers?

Many of our databases store numeric tracking codes (like serial numbers) as integers. There is little chance of these codes every getting alphabetic characters, but it still seems like an incorrect ...
1
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2answers
262 views

Join on different types

In a database I have two tables: The first has a field named taxonomy_id that is an integer The latter has a field named ID that is a character varying The two tables are related: if it exists a ...
2
votes
1answer
99 views

Why does postgres use more space for a time with timezone than a timestamp with timezone?

The documentation on date/time data types state that timestamp with timezone takes 8 bytes, while time with timezone takes 12 bytes. They both have the same resolution (1 microsecond), and on the face ...
2
votes
1answer
614 views

Trigger doesn't run when value of a column changes from null to 1

I have this trigger: delimiter $$ create trigger tr after update on t1 for each row begin if new.col1 !=old.col1 then update t2 set col2 =1 where t2.col3=t1.col3; end if; end $$ This ...
3
votes
2answers
2k views

What data type should I use: ENUM, TINYINT, or CHAR?

I'm creating a new table and I would like to do it right. The table will be a list of members with their Professional Type and Decile associated. The Professional Type is a 3-character string. There ...
1
vote
1answer
112 views

Changing TEXT to VARCHAR

In a MySQL database (InnoDB) we have a table containing roughly 60.000.000 rows. One of the columns is of type text. Currently the longest entry has length 360 (found using SELECT MAX(LENGTH(value)) ...
24
votes
6answers
14k views

In what data type should I store an email address in database?

I understand that an 254 character email address is valid, but implementations I have researched tend to use a varchar(60) to varchar(80) or equivalent. For example: this SQL Server recommendation ...
0
votes
2answers
90 views

Adding a bool column; tracking untouched vs. false

[backstory] I have a simple database of our current Widget inventory. It averages just dozen columns across five or six tables, but has a huge number of records already. Some Widgets came with ...
6
votes
3answers
2k views

How to pass a table type with an array field to a function in postgresql

i have a table called book CREATE TABLE book ( id smallint NOT NULL DEFAULT 0, bname text, btype text, bprices numeric(11,2)[], CONSTRAINT key PRIMARY KEY (id ) ) and a ...
2
votes
1answer
1k views

Storing IPv4 and IPv6 hosts and networks

I have to store the IPv4/v6 address and networks(CIDR notation) in a MySQL database. Unfortunately, I am constrained to use Mysql. So, I'm looking for the equivalent of the inet type of PostgreSql. ...
2
votes
1answer
108 views

Oracle Table Design, Storing Small Values

In Oracle if you want to store a small value, such as a one digit code (e.g. 0, 1, 2, 3 4, or Null; or Null, or 1; or 1, or 2), what is the space optimal way to store such a value. Currently I'm ...
2
votes
1answer
620 views

SQL Server - storing ulong as primary key

I need to store ulong values as a primary key in SQL Server. Since SQL Server doesn't have a ulong datatype (or for that matter anything unsigned), the only way to go is to have column as ...
0
votes
2answers
146 views

looping through a table type variable

I have a function that has one parameter of a table type, i want to loop through all the fields and return the column that has a null or empty value. CREATE OR REPLACE FUNCTION ...
3
votes
1answer
2k views

query to identify all data types used in postgresql database tables

I don't want to know all data types, just all data types used in my database. Can this information be queried? PostgreSQL 8.4 and 9.x versions I currently need to know all data types for over 200 ...
1
vote
1answer
596 views

How can I restore the sql_variant_property of baseType back to a table variable in SQL Server

Ok, I know the title is confusing but here it goes. BTW I am using SQL Server 2008 I have a table that I am trying to use as a storage container. It has 3 columns: reportID integer, dataLabel ...
0
votes
1answer
1k views

What is the difference between int(8) and int(5) in mysql? [duplicate]

I found out, that if you have a field defined as INT(8) without ZEROFILL it will behave exactly as INT(5) in both cases the maximum value is −2,147,483,648 to 2,147,483,647, from −(2^31) to 2^31 − 1 ...
14
votes
2answers
969 views

Does varchar size matter in temporary tables?

There is a debate at my wife's work about just using varchar(255) for all varchar fields in temporary tables in stored procedures. Basically, one camp wants to use 255 because it will always work ...
4
votes
1answer
8k views

What is the benefit of using BOOLEAN over TINYINT(1)?

From MySQL manual, it says: BOOL, BOOLEAN These types are synonyms for TINYINT(1). A value of zero is considered false. Nonzero values are considered true: I created a BOOLEAN column with ...
1
vote
1answer
5k views

Table schema column data type equivalents for Netezza 6 to SQL Server 2008

I'm trying to find a data type equivalents for data types in Netezza when migrating table schema to SQL Server. Where can I find a complete list? When getting down to brass tacks, I am specifically ...
0
votes
4answers
621 views

Writing SQL statement in sqlcmd to hide the milliseconds for column type of time

I have a table called testtable that have a column named expire_time of type [time] The problem is that when I type the following in sqlcmd: select * from testtable It will return the following: ...
0
votes
1answer
560 views

timeout on updating nvarchar(max) after converting datatype

I recently Upgraded to 2008 Enterprise and took the opportunity to change the biggest table in my db with the maintenance window. ran the following to change my ntext field ALTER TABLE ...
3
votes
1answer
581 views

Does creating an index on BIT(n) attribute in MySQL make sense?

I am working on a very specific thing and I need to use BIT(n) attributes and efficiently search through them. n is generally not a power of 2. I've seen some mentions on the internet that BIT ...
-2
votes
1answer
3k views

What are performance benefits when using number type instead of using char/varchar?

From various posts, I have summarized about using number type instead of char/varchar for PK: If you choose char/varchar type for PK and your values are short (just some alpha numberic codes) then it ...
4
votes
1answer
586 views

Why does using a Real data type in a mathematical equation return an incorrect result?

I was trying to figure out the source of what appeared to be a rounding error today, and discovered that one of the columns used in a mathematical equation was using the real data type, and this is ...
4
votes
1answer
113 views

Data type for a fuzzy date?

I want to store partial information related to a date. I might know the year and month but not the day. I might know the day and month but not the year. I might know the date lies in an open or closed ...
3
votes
1answer
2k views

Oracle integer to number conversion

According to the Oracle documentation, creating a table with a column of ANSI type INT, Oracle will convert it to NUMBER(38). According to the same document, NUMBER(38) is supposed to be a NUMBER ...
8
votes
3answers
520 views

What should I use? A string or 15 integer fields?

I am developing a student tracking program where I need to store 15 exam marks. I can store the marks as a string and split them up when I need to, for purposes such as performing arithmetical ...
5
votes
2answers
406 views

Determining the optimal Column Widths from a .csv File

I want to import a .CSV file into a MySQL Table. I would like to determine the optimal column widths to use based on the actual data contained in the CSV file. Are there any scripts or utilities to ...
2
votes
3answers
145 views

How to restrict sequence like ID type to C type like int64_t, uint64_t, int32_t?

In C99 I can be pretty clear about the size/domain of an integer type. When interfacing a SQL database like Oracle or Postgresql from a C program I want to create a table with integer types that ...
5
votes
2answers
3k views

Designing a user authenication (Roles & Rights) module

I am trying to model a User Authentication module for a MS SQL Server database that will be the back end to a Delphi UI Application. Basically, I want to have user accounts where the user belongs to ...
0
votes
1answer
44 views

Does a numeric field always use the same disk space?

When you have a numeric field in MySQL(MYISAM) (E.g. Integer) will it always use the same disk space, no matter what number is actually stored?
4
votes
1answer
200 views

How to set constraints on UDT in SQL Server 2005 - 2012

I'm creating my UDT: CREATE TYPE [dbo].[Code] FROM VARCHAR(20) NOT NULL As RULES and DEFAULTS are considered deprecated, what is the recommended way to set constraint on my type to make sure that ...
3
votes
2answers
4k views

changing float->numeric casts from assignment to implicit, dangerous?

In porting an application to PostgreSQL (9.1), one odd SQL incompatibility I've discovered concerns the round() function, specifically the version that takes a second argument indicating the rounding ...
4
votes
2answers
938 views

Change column data type across database

I have a bunch of tables with many columns of data type ntext. I wish to change all such columns in all tables of a particular database to nvarchar(max), because of planned deprecation (EDIT: also ...
6
votes
3answers
3k views

Should I add an arbitrary length limit to VARCHAR columns?

According to PostgreSQL's docs, there's no performance difference between VARCHAR, VARCHAR(n) and TEXT. Should I add an arbitrary length limit to a name or address column?