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

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1
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1answer
513 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") ...
3
votes
2answers
2k 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
402 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
110 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 ...
1
vote
1answer
194 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
votes
1answer
921 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?
15
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2answers
26k views

What is the difference between MySQL VARCHAR and TEXT data types?

After version 5.0.3 (which allowed VARCHAR to be 65,535 bytes and stopped truncating trailing spaces), is there any major difference between these two data types? I was reading the list of ...
9
votes
2answers
3k views

SQL Server Decimal(9, 0) vs INT

One of our customers uses for some columns the datatype DECIMAL(18,0) in his SQL Server 2008R2 database. Because the columns grow quite slowly, he recently proposed to change the datatype to ...
3
votes
1answer
10k views

How can I convert from Double Precision to Bigint with PostgreSQL?

I need to convert a value of Double Precision to Bigint with PostgreSQL. How can I do that? I have tried with to_bigint(myvalue) but that function didn't exist.
1
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2answers
224 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
4k 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
355 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, ...
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1answer
206 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
1answer
271 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), ...
1
vote
2answers
681 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 ...
0
votes
2answers
186 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
vote
2answers
193 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
88 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
525 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
110 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)) ...
23
votes
6answers
11k 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 ...
3
votes
2answers
4k views

what is bigger than a longblob?

the longblob is the biggest data type of Mysql. If I want to save something bigger than 4gb (longblob) how can I do?. I'm talking about Mysql v-5.+
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 ...
15
votes
5answers
7k views

Performance implications of MySQL VARCHAR sizes

Is there a performance difference in MySQL between varchar sizes? For example, varchar(25) and varchar(64000). If not, is there a reason not to declare all varchars with the max size just to ensure ...
5
votes
2answers
392 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 ...
6
votes
3answers
1k 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 ...
0
votes
2answers
137 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 ...
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
105 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
552 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 ...
1
vote
1answer
363 views

Is it possible to fetch or update table data by table field type?

Is it possible to fetch or update table data by field type? If possible please tell me with a sample code.
6
votes
2answers
664 views

What are the pros/cons of splitting date and time into separate fields vs. using the datetime data type and storing the date in a single field?

My database is extremely large and growing at a rate of ~20m rows/day. I have timestamp data that is important but most of the reporting is based on date ranges and week over week or month over month ...
2
votes
1answer
5k views

Column size with datatype decimal

According to BOL for SQL Server 2008 R2 the data type decimal requires the following storage bytes: Precision Storage bytes 1 - 9 => 5 10-19 => 9 20-28 => 13 29-38 ...
1
vote
1answer
555 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 ...
14
votes
2answers
863 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
7k 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
4k 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
574 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
479 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 ...
-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 ...
3
votes
1answer
529 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 ...
4
votes
1answer
563 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
109 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 ...
4
votes
2answers
1k views

What is the best identifier for a UserID? 64 bit integers, UUID V5, or 64 character SHA256 UID?

I wish to future-proof my application. What is the best type of identifier to use? I am considering: 64 bit Integer UUID 64 character SHA256 I am not developing a distributed system, so is ...
3
votes
1answer
1k 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
518 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 ...
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 ...
4
votes
1answer
197 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 ...
12
votes
1answer
14k views

INT(5) vs SMALLINT(5)

In MySQL table definitions is there a different between INT(5) and SMALLINT(5)? Or do they both represent the same size?