Date and time types¶
This topic will describe the DATE
, TIME
, DATETIME
, and TIMESTAMP
types.
While inserting time-type property values, except for TIMESTAMP
, NebulaGraph transforms them to a UTC time according to the time zone specified with the timezone_name
parameter in the configuration files.
Note
To change the time zone, modify the timezone_name
value in the configuration files of all NebulaGraph services.
date()
,time()
,datetime()
, andtimestamp()
all accept empty parameters to return the current date, time, and datetime.
date()
,time()
, anddatetime()
all accept the property name to return a specific property value of itself. For example,date().month
returns the current month, whiletime("02:59:40").minute
returns the minutes of the importing time.
OpenCypher Compatibility¶
In nGQL:
- Year, month, day, hour, minute, and second are supported, while the millisecond is not supported.
localdatetime()
andduration()
are not supported.
- Most string time formats are not supported. The exceptions are
YYYY-MM-DDThh:mm:ss
andYYYY-MM-DD hh:mm:ss
.
DATE¶
The DATE
type is used for values with a date part but no time part. Nebula Graph retrieves and displays DATE
values in the YYYY-MM-DD
format. The supported range is -32768-01-01
to 32767-12-31
.
The properties of date()
include year
, month
, and day
.
TIME¶
The TIME
type is used for values with a time part but no date part. Nebula Graph retrieves and displays TIME
values in hh:mm:ss.msmsmsususus
format. The supported range is 00:00:00.000000
to 23:59:59.999999
.
The properties of time()
include hour
, minute
, and second
.
DATETIME¶
The DATETIME
type is used for values that contain both date and time parts. Nebula Graph retrieves and displays DATETIME
values in YYYY-MM-DDThh:mm:ss.msmsmsususus
format. The supported range is -32768-01-01T00:00:00.000000
to 32767-12-31T23:59:59.999999
.
The properties of datetime()
include year
, month
, day
, hour
, minute
, and second
.
TIMESTAMP¶
The TIMESTAMP
data type is used for values that contain both date and time parts. It has a range of 1970-01-01T00:00:01
UTC to 2262-04-11T23:47:16
UTC.
TIMESTAMP
has the following features:
- Stored and displayed in the form of a timestamp, such as
1615974839
, which means2021-03-17T17:53:59
.
- Supported
TIMESTAMP
querying methods: timestamp andtimestamp()
function.
- Supported
TIMESTAMP
inserting methods: timestamp,timestamp()
function, andnow()
function.
-
timestamp()
function accepts empty parameters to get the timestamp of the current time zone and also accepts a string type parameter.# Return the current time. nebula> RETURN timestamp(); +-------------+ | timestamp() | +-------------+ | 1625469277 | +-------------+ # Return the specified time. nebula> RETURN timestamp("2021-07-05T06:18:43.984000"); +-----------------------------------------+ | timestamp("2021-07-05T06:18:43.984000") | +-----------------------------------------+ | 1625465923 | +-----------------------------------------+
- The underlying storage data type is int64.
Examples¶
-
Create a tag named
date1
with three properties:DATE
,TIME
, andDATETIME
.nebula> CREATE TAG IF NOT EXISTS date1(p1 date, p2 time, p3 datetime);
-
Insert a vertex named
test1
.nebula> INSERT VERTEX date1(p1, p2, p3) VALUES "test1":(date("2021-03-17"), time("17:53:59"), datetime("2021-03-17T17:53:59"));
-
Return the content of the property
p1
ontest1
.nebula> CREATE TAG INDEX IF NOT EXISTS date1_index ON date1(p1); nebula> REBUILD TAG INDEX date1_index; nebula> MATCH (v:date1) RETURN v.p1; +------------+ | v.p1 | +------------+ | 2021-03-17 | +------------+
-
Create a tag named
school
with the property ofTIMESTAMP
.nebula> CREATE TAG IF NOT EXISTS school(name string , found_time timestamp);
-
Insert a vertex named
DUT
with a found-time timestamp of"1988-03-01T08:00:00"
.# Insert as a timestamp. The corresponding timestamp of 1988-03-01T08:00:00 is 573177600, or 573206400 UTC. nebula> INSERT VERTEX school(name, found_time) VALUES "DUT":("DUT", 573206400); # Insert in the form of date and time. nebula> INSERT VERTEX school(name, found_time) VALUES "DUT":("DUT", timestamp("1988-03-01T08:00:00"));
-
Insert a vertex named
dut
and store time withnow()
ortimestamp()
functions.# Use now() function to store time nebula> INSERT VERTEX school(name, found_time) VALUES "dut":("dut", now()); # Use timestamp() function to store time nebula> INSERT VERTEX school(name, found_time) VALUES "dut":("dut", timestamp());
You can also use WITH
statement to set a specific date and time. For example:
nebula> WITH time({hour: 12, minute: 31, second: 14, millisecond:111, microsecond: 222}) AS d RETURN d;
+-----------------+
| d |
+-----------------+
| 12:31:14.111222 |
+-----------------+
nebula> WITH date({year: 1984, month: 10, day: 11}) AS x RETURN x + 1;
+------------+
| (x+1) |
+------------+
| 1984-10-12 |
+------------+