time (Transact-SQL) - SQL Server (2023)

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Applies to: time (Transact-SQL) - SQL Server (1) SQL Server time (Transact-SQL) - SQL Server (2) Azure SQL Database time (Transact-SQL) - SQL Server (3) Azure SQL Managed Instance time (Transact-SQL) - SQL Server (4) Azure Synapse Analytics time (Transact-SQL) - SQL Server (5) Analytics Platform System (PDW)

Defines a time of a day. The time is without time zone awareness and is based on a 24-hour clock.

Note

Informatica information is provided for PDW customers using the Informatica Connector.

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time Description

PropertyValue
Syntaxtime [ (fractional second scale) ]
UsageDECLARE @MyTime time(7)

CREATE TABLE Table1 ( Column1 time(7) )

fractional seconds scaleSpecifies the number of digits for the fractional part of the seconds.

This can be an integer from 0 to 7. For Informatica, this can be an integer from 0 to 3.

The default fractional scale is 7 (100ns).

Default string literal format

(used for down-level client)

hh:mm:ss[.nnnnnnn] for Informatica)

For more information, see the Backward Compatibility for Down-level Clients section.

Range00:00:00.0000000 through 23:59:59.9999999 (00:00:00.000 through 23:59:59.999 for Informatica)
Element rangeshh is two digits, ranging from 0 to 23, that represent the hour.

mm is two digits, ranging from 0 to 59, that represent the minute.

ss is two digits, ranging from 0 to 59, that represent the second.

n* is zero to seven digits, ranging from 0 to 9999999, that represent the fractional seconds. For Informatica, n* is zero to three digits, ranging from 0 to 999.

Character length8 positions minimum (hh:mm:ss) to 16 maximum (hh:mm:ss.nnnnnnn). For Informatica, the maximum is 12 (hh:mm:ss.nnn).
Precision, scale

(user specifies scale only)

See the table below.
Storage size5 bytes, fixed, is the default with the default of 100ns fractional second precision. In Informatica, the default is 4 bytes, fixed, with the default of 1ms fractional second precision.
Accuracy100 nanoseconds (1 millisecond in Informatica)
Default value00:00:00

This value is used for the appended time part for implicit conversion from date to datetime2 or datetimeoffset.

User-defined fractional second precisionYes
Time zone offset aware and preservationNo
Daylight saving awareNo
Specified scaleResult (precision, scale)Column length (bytes)Fractional

seconds

precision

time(16,7) [(12,3) in Informatica]5 (4 in Informatica)7 (3 in Informatica)
time(0)(8,0)30-2
time(1)(10,1)30-2
time(2)(11,2)30-2
time(3)(12,3)43-4
time(4)

Not supported in Informatica.

(13,4)43-4
time(5)

Not supported in Informatica.

(14,5)55-7
time(6)

Not supported in Informatica.

(15,6)55-7
time(7)

Not supported in Informatica.

(16,7)55-7

Supported String Literal Formats for time

The following table shows the valid string literal formats for the time data type.

SQL ServerDescription
hh:mm[:ss][:fractional seconds][AM][PM]

hh:mm[:ss][.fractional seconds][AM][PM]

hhAM[PM]

hh AM[PM]

The hour value of 0 represents the hour after midnight (AM), regardless of whether AM is specified. PM cannot be specified when the hour equals 0.

Hour values from 01 through 11 represent the hours before noon if neither AM nor PM is specified. The values represent the hours before noon when AM is specified. The values represent hours after noon if PM is specified.

The hour value 12 represents the hour that starts at noon if neither AM nor PM is specified. If AM is specified, the value represents the hour that starts at midnight. If PM is specified, the value represents the hour that starts at noon. For example, 12:01 is 1 minute after noon, as is 12:01 PM; and 12:01 AM is one minute after midnight. Specifying 12:01 AM is the same as specifying 00:01 or 00:01 AM.

Hour values from 13 through 23 represent hours after noon if AM or PM is not specified. The values also represent the hours after noon when PM is specified. AM cannot be specified when the hour value is from 13 through 23.

An hour value of 24 is not valid. To represent midnight, use 12:00 AM or 00:00.

Milliseconds can be preceded by either a colon (:) or a period (.). If a colon is used, the number means thousandths-of-a-second. If a period is used, a single digit means tenths-of-a-second, two digits mean hundredths-of-a-second, and three digits mean thousandths-of-a-second. For example, 12:30:20:1 indicates 20 and one-thousandth seconds past 12:30; 12:30:20.1 indicates 20 and one-tenth seconds past 12:30.

ISO 8601Notes
hh:mm:ss

hh:mm[:ss][.fractional seconds]

hh is two digits, ranging from 0 to 23, that represent the number of hours in the time zone offset.

mm is two digits, ranging from 0 to 59, that represent the number of additional minutes in the time zone offset.

ODBCNotes
{t 'hh:mm:ss[.fractional seconds]'}ODBC API specific.

Compliance with ANSI and ISO 8601 Standards

Using hour 24 to represent midnight and leap second over 59 as defined by ISO 8601 (5.3.2 and 5.3) are not supported to be backward compatible and consistent with the existing date and time types.

The default string literal format (used for down-level client) will align with the SQL standard form, which is defined as hh:mm:ss[.nnnnnnn]. This format resembles the ISO 8601 definition for TIME excluding fractional seconds.

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Backward Compatibility for Down-level Clients

Some down-level clients do not support the time, date, datetime2 and datetimeoffset data types. The following table shows the type mapping between an up-level instance of SQL Server and down-level clients.

SQL Server data typeDefault string literal format passed to down-level clientDown-level ODBCDown-level OLEDBDown-level JDBCDown-level SQLCLIENT
timehh:mm:ss[.nnnnnnn]SQL_WVARCHAR or SQL_VARCHARDBTYPE_WSTRor DBTYPE_STRJava.sql.StringString or SqString
dateYYYY-MM-DDSQL_WVARCHAR or SQL_VARCHARDBTYPE_WSTRor DBTYPE_STRJava.sql.StringString or SqString
datetime2YYYY-MM-DD hh:mm:ss[.nnnnnnn]SQL_WVARCHAR or SQL_VARCHARDBTYPE_WSTRor DBTYPE_STRJava.sql.StringString or SqString
datetimeoffsetYYYY-MM-DD hh:mm:ss[.nnnnnnn] [+|-]hh:mmSQL_WVARCHAR or SQL_VARCHARDBTYPE_WSTRor DBTYPE_STRJava.sql.StringString or SqString

Converting Date and Time Data

When you convert to date and time data types, SQL Server rejects all values it cannot recognize as dates or times. For information about using the CAST and CONVERT functions with date and time data, see CAST and CONVERT (Transact-SQL)

Converting time(n) Data Type to Other Date and Time Types

This section describes what occurs when a time data type is converted to other date and time data types.

When the conversion is to time(n), the hour, minute, and seconds are copied. When the destination precision is less than the source precision, the fractional seconds is rounded up to fit the destination precision. The following example shows the results of converting a time(4) value to a time(3) value.

DECLARE @timeFrom time(4) = '12:34:54.1237'; DECLARE @timeTo time(3) = @timeFrom; SELECT @timeTo AS 'time(3)', @timeFrom AS 'time(4)'; --Results --time(3) time(4) -------------- ------------- --12:34:54.124 12:34:54.1237 -- --(1 row(s) affected) 

If the conversion is to date, the conversion fails, and error message 206 is raised: "Operand type clash: date is incompatible with time".

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When the conversion is to datetime, hour, minute, and second values are copied; and the date component is set to '1900-01-01'. When the fractional seconds precision of the time(n) value is greater than three digits, the datetime result will be truncated. The following code shows the results of converting a time(4) value to a datetime value.

DECLARE @time time(4) = '12:15:04.1237'; DECLARE @datetime datetime= @time; SELECT @time AS '@time', @datetime AS '@datetime'; --Result --@time @datetime --------------- ----------------------- --12:15:04.1237 1900-01-01 12:15:04.123 -- --(1 row(s) affected) 

When the conversion is to smalldatetime, the date is set to '1900-01-01', and the hour and minute values are rounded up. The seconds and fractional seconds are set to 0. The following code shows the results of converting a time(4) value to a smalldatetime value.

-- Shows rounding up of the minute value. DECLARE @time time(4) = '12:15:59.9999'; DECLARE @smalldatetime smalldatetime= @time; SELECT @time AS '@time', @smalldatetime AS '@smalldatetime'; --Result @time @smalldatetime ---------------- ----------------------- 12:15:59.9999 1900-01-01 12:16:00-- --(1 row(s) affected) -- Shows rounding up of the hour value. DECLARE @time time(4) = '12:59:59.9999'; DECLARE @smalldatetime smalldatetime= @time; SELECT @time AS '@time', @smalldatetime AS '@smalldatetime'; @time @smalldatetime ---------------- ----------------------- 12:59:59.9999 1900-01-01 13:00:00 (1 row(s) affected) 

If the conversion is to datetimeoffset(n), the date is set to '1900-01-01', and the time is copied. The time zone offset is set to +00:00. When the fractional seconds precision of the time(n) value is greater than the precision of the datetimeoffset(n) value, the value is rounded up to fit. The following example shows the results of converting a time(4) value to a datetimeoffset(3) type.

DECLARE @time time(4) = '12:15:04.1237'; DECLARE @datetimeoffset datetimeoffset(3) = @time; SELECT @time AS '@time', @datetimeoffset AS '@datetimeoffset'; --Result --@time @datetimeoffset --------------- ------------------------------ --12:15:04.1237 1900-01-01 12:15:04.124 +00:00 -- --(1 row(s) affected) 

When converting to datetime2(n), the date is set to '1900-01-01', the time component is copied, and the time zone offset is set to 00:00. When the fractional seconds precision of the datetime2(n) value is greater than the time(n) value, the value will be rounded up to fit. The following example shows the results of converting a time(4) value to a datetime2(2) value.

DECLARE @time time(4) = '12:15:04.1237'; DECLARE @datetime2 datetime2(3) = @time; SELECT @datetime2 AS '@datetime2', @time AS '@time'; --Result --@datetime2 @time ------------------------- ------------- --1900-01-01 12:15:04.124 12:15:04.1237 -- --(1 row(s) affected) 

Converting String Literals to time(n)

Conversions from string literals to date and time types are permitted if all parts of the strings are in valid formats. Otherwise, a runtime error is raised. Implicit conversions or explicit conversions that do not specify a style, from date and time types to string literals will be in the default format of the current session. The following table shows the rules for converting a string literal to the time data type.

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Input string literalConversion Rule
ODBC DATEODBC string literals are mapped to the datetime data type. Any assignment operation from ODBC DATETIME literals into timetypes will cause an implicit conversion between datetime and this type as defined by the conversion rules.
ODBC TIMESee ODBC DATE rule above.
ODBC DATETIMESee ODBC DATE rule above.
DATE onlyDefault values are supplied.
TIME onlyTrivial
TIMEZONE onlyDefault values are supplied.
DATE + TIMEThe TIME part of the input string is used.
DATE + TIMEZONENot allowed.
TIME + TIMEZONEThe TIME part of the input string is used.
DATE + TIME + TIMEZONEThe TIME part of local DATETIME will be used.

Examples

A. Comparing date and time Data Types

The following example compares the results of casting a string to each date and time data type.

SELECT CAST('2007-05-08 12:35:29. 1234567 +12:15' AS time(7)) AS 'time' ,CAST('2007-05-08 12:35:29. 1234567 +12:15' AS date) AS 'date' ,CAST('2007-05-08 12:35:29.123' AS smalldatetime) AS 'smalldatetime' ,CAST('2007-05-08 12:35:29.123' AS datetime) AS 'datetime' ,CAST('2007-05-08 12:35:29. 1234567 +12:15' AS datetime2(7)) AS 'datetime2' ,CAST('2007-05-08 12:35:29.1234567 +12:15' AS datetimeoffset(7)) AS 'datetimeoffset'; 
Data typeOutput
time12:35:29. 1234567
date2007-05-08
smalldatetime2007-05-08 12:35:00
datetime2007-05-08 12:35:29.123
datetime22007-05-08 12:35:29. 1234567
datetimeoffset2007-05-08 12:35:29.1234567 +12:15

B. Inserting Valid Time String Literals into a time(7) Column

The following table lists different string literals that can be inserted into a column of data type time(7) with the values that are then stored in that column.

String literal format typeInserted string literaltime(7) value that is storedDescription
SQL Server'01:01:01:123AM'01:01:01.1230000When a colon (:) comes before fractional seconds precision, scale cannot exceed three positions or an error will be raised.
SQL Server'01:01:01.1234567 AM'01:01:01.1234567When AM or PM is specified, the time is stored in 24-hour format without the literal AM or PM
SQL Server'01:01:01.1234567 PM'13:01:01.1234567When AM or PM is specified, the time is stored in 24-hour format without the literal AM or PM
SQL Server'01:01:01.1234567PM'13:01:01.1234567A space before AM or PM is optional.
SQL Server'01AM'01:00:00.0000000When only the hour is specified, all other values are 0.
SQL Server'01 AM'01:00:00.0000000A space before AM or PM is optional.
SQL Server'01:01:01'01:01:01.0000000When fractional seconds precision is not specified, each position that is defined by the data type is 0.
ISO 8601'01:01:01.1234567'01:01:01.1234567To comply with ISO 8601, use 24-hour format, not AM or PM.
ISO 8601'01:01:01.1234567 +01:01'01:01:01.1234567The optional time zone difference (TZD) is allowed in the input but is not stored.

C. Inserting Time String Literal into Columns of Each date and time Date Type

In the following table the first column shows a time string literal to be inserted into a database table column of the date or time data type shown in the second column. The third column shows the value that will be stored in the database table column.

Inserted string literalColumn data typeValue that is stored in columnDescription
'12:12:12.1234567'time(7)12:12:12.1234567If the fractional seconds precision exceeds the value specified for the column, the string will be truncated without error.
'2007-05-07'dateNULLAny time value will cause the INSERT statement to fail.
'12:12:12'smalldatetime1900-01-01 12:12:00Any fractional seconds precision value will cause the INSERT statement to fail.
'12:12:12.123'datetime1900-01-01 12:12:12.123Any second precision longer than three positions will cause the INSERT statement to fail.
'12:12:12.1234567'datetime2(7)1900-01-01 12:12:12.1234567If the fractional seconds precision exceeds the value specified for the column, the string will be truncated without error.
'12:12:12.1234567'datetimeoffset(7)1900-01-01 12:12:12.1234567 +00:00If the fractional seconds precision exceeds the value specified for the column, the string will be truncated without error.

See Also

CAST and CONVERT (Transact-SQL)

FAQs

What is a good query execution time? ›

10 ms or less – good performance. 10-100 ms – optimization is recommended. more than 100 ms – poor performance, optimization is needed.

How many days does it take to complete SQL course? ›

How Long Does it Take to Learn SQL? Because SQL is a relatively simple language, learners can expect to become familiar with the basics within two to three weeks. That said, if you're planning on using SQL skills at work, you'll probably need a higher level of fluency.

How to optimize SQL query performance in SQL Server? ›

The way to make a query run faster is to reduce the number of calculations that the software (and therefore hardware) must perform. To do this, you'll need some understanding of how SQL actually makes calculations.

Why does query take so long to execute? ›

There are a number of things that may cause a query to take longer time to execute: Inefficient query – Use non-indexed columns while lookup or joining, thus MySQL takes longer time to match the condition. Table lock – The table is locked, by global lock or explicit table lock when the query is trying to access it.

Can I learn SQL in 15 days? ›

1 hour per day, for just 15 days and you will be fluent in SQL! That's the only course you need to completely master SQL. You will be guided step-by-step from beginner to absolute expert in SQL.

Can I learn SQL in 2 weeks? ›

Everyone's different, but learning basic SQL statements can take anywhere from a couple of hours to a couple of weeks. It can take months to master them, but once you understand the concepts behind statements like INSERT, UPDATE, and DELETE, you'll be very well placed to use those statements in the real world.

Can I learn SQL in 10 days? ›

It should take an average learner about two to three weeks to master the basic concepts of SQL and start working with SQL databases. But in order to start using them effectively in real-world scenarios, you'll need to become quite fluent; and that takes time.

What affects execution speed? ›

Clock speed, cache and core count

Additionally, (also in the above link), as the frequency increases, the power draw and heat generated by the CPU also increase. Again, as already discussed, the cache and core count will also affect the execution speed.

What is the key to successful execution? ›

Strategy execution is the implementation of a strategic plan in an effort to reach organizational goals. It comprises the daily structures, systems, and operational goals that set your team up for success. Even the best strategic plans can fall flat without the right execution.

What does execution time depend on? ›

The execution time of an instruction depends in part on the behavior of other instructions in the pipeline. Two instructions that compete for the same resource will execute more slowly when executed together than if they were executed at widely separated times. The memory system is an even larger source of variation.

Does indexing improve query performance? ›

Indexing makes columns faster to query by creating pointers to where data is stored within a database. Imagine you want to find a piece of information that is within a large database. To get this information out of the database the computer will look through every row until it finds it.

How do I know which SQL Server query is running slow? ›

You can view this by Right Clicking on Instance Name in SQL Server Management Studio and selecting “Activity Monitor”. Activity monitor tells you what the current and recent activities are in your SQL Server Instance. The above screenshot displays an overview window for the Activity Monitor.

How to check how much time a query will take in SQL Server? ›

Go to Menu >> Query >> Select Include client Statistics. Execute your query. In the results panel, you can see a new tab Client Statistics. Go to the Client Statistics tab to see the execution time.

Is CTE better than subquery? ›

Advantages of Using CTE

CTE can be more readable: Another advantage of CTE is CTE is more readable than Subqueries. Since CTE can be reusable, you can write less code using CTE than using a subquery. Also, people tend to follow logic and ideas easier in sequence than in a nested fashion.

What is the fastest SQL database? ›

MongoDB is suitable for hierarchical data storage and is almost 100 times faster than Relational Database Management System (RDBMS). This platform centers around the CAP theorem (Consistency, Availability, and Partition tolerance.)

How do I handle a large table in SQL Server? ›

The most recommended and best option is to have a STANDBY server, restore the backup of the production database on that server, and then run the DBCC command. If the consistency checks run ok on the standby database, the production database should be ok as it is the source of the standby.

What is considered a slow query? ›

The slow query log consists of SQL statements that take more than long_query_time seconds to execute and require at least min_examined_row_limit rows to be examined. The slow query log can be used to find queries that take a long time to execute and are therefore candidates for optimization.

Is SQL enough to get a job? ›

If you're looking for your first job in data, it turns out knowing SQL is even more critical. For data analyst roles, SQL is again the most in-demand skill, listed in a whopping 61% of job posts. For data analyst roles on Indeed, SQL appears as follows: 1.7 times more than Python.

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Generally speaking, SQL is an easy language to learn. If you understand programming and already know some other languages, you can learn SQL in a few weeks. If you're a beginner, completely new to programming, it can take longer.

Is SQL easier than coding? ›

Because of its narrow application domain, SQL is relatively easier to learn than most general-purpose programming languages. We encourage you to follow DataCamp's SQL Fundamentals track, where we take you from being a beginner to a pro in SQL with 5 courses in just 21 hours.

Is SQL easier than Python? ›

SQL is certainly an easier language to learn than Python. It has a very basic syntax that has the sole purpose of communicating with relational databases. Since a great amount of data is stored in relational databases, retrieving data using SQL queries is often the first step in any data analysis project.

Do hackers need to learn SQL? ›

SQL skills are essential to becoming an effective hacker. Hacking tools are programs that simplify the process of identifying and exploiting weaknesses in computer systems.

Is SQL worth learning 2022? ›

Yes, SQL mastery is still valuable in 2022. This is because SQL is a popular language in programming and is a top choice for software applications to this day. Many of the top RDBMS frameworks use SQL. SQL experts are flexible and versatile in handling various database management systems.

How do I memorize SQL commands? ›

So try to memorise the following consecutive statements: SELECT→FROM→WHERE. Next, remember that the SELECT statement refers to the column names, the FROM keyword refers to the table/database used, and the WHERE clause refers to specific conditions that are investigated by the user.

Can I learn basic SQL in a day? ›

First, you'll learn how to extract data from one table. Later, you'll discover how to work with more than one table and group query results. All of this you can immediately apply in your everyday work (if you work with data, that is). The SQL Basics course should take you a maximum of 10 hours to complete.

What is considered a long running query? ›

The threshold of when a SQL query is considered to be long running is controlled by the Business Central Server configuration setting SqlLongRunningThreshold. The default value is 1000 milliseconds (ms).

How long should a MySQL query take? ›

There's no worry as long as there's no problem. A query can take up to one hour if it crunches extremely large amount of data once every 6 months in a system where only it is running. It won't be a problem. Another query can take 100ms only but it's on a web server and 1000 persons are connecting simultaneously!

How do you optimize a poor performing query? ›

Steps to take to improve performance of queries:

- Create all primary and foreign keys and relationships among tables. - Avoid using Select*, rather mention the needed columns and narrow the resultset as needed. - Implement queries as stored procedures. - Have a WHERE Clause in all SELECT queries.

How to check slowness in SQL Server? ›

If SQL Server and the OS indicate that the I/O subsystem is slow, check if the cause is the system being overwhelmed beyond capacity. You can check capacity by looking at I/O counters Disk Bytes/Sec , Disk Read Bytes/Sec , or Disk Write Bytes/Sec .

What are the 4 types of queries? ›

They are: Select queries • Action queries • Parameter queries • Crosstab queries • SQL queries.

Is there a limit to how long a SQL query can be? ›

The maximum standard SQL query length is 1024.00K characters, including comments.

What is the maximum length of SQL query? ›

65,534 is the maximum number of characters that can be entered in a SQL Query, for a Command Object, in Crystal Reports. Note: If your SQL Query is larger than 64KB, create a stored procedure in your database, then create a report based on the Stored Procedure.

What could most likely cause a SQL query to run as slow as 5 minutes? ›

What could most likely cause a SQL query to run as slow as 5 minutes? Ans. Most probably, a sudden surge in the volume of data in a particular table could slow down the output of a SQL query. So collect the required stats for the target table.

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