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v5.0

Documentation:v5.0

Supported Versions:
Current(v5.0)/
v3.1

Other Versions:
v3.0/
v2.1/
v2.0/
v1.1

Type Conversion Functions(1)

  • cash_words(money)

    Description: Type conversion function, which converts money into text.

    Example:

    MogDB=# SELECT cash_words('1.23');
            cash_words
-----------------------------------
 One dollar and twenty three cents
(1 row)

  • cast(x as y)

    Description: Converts x into the type specified by y.

    Example:

    MogDB=# SELECT cast('22-oct-1997' as timestamp);
      timestamp
---------------------
 1997-10-22 00:00:00
(1 row)

  • hextoraw(raw)

    Description: Converts a string in hexadecimal format into the raw type.

    Return type: raw

    Example:

    MogDB=# SELECT hextoraw('7D');
 hextoraw
----------
 7D
(1 row)

  • numtoday(numeric)

    Description: Converts values of the number type into the timestamp of the specified type.

    Return type: timestamp

    Example:

    MogDB=# SELECT numtoday(2);
 numtoday
----------
 2 days
(1 row)

  • pg_systimestamp()

    Description: Obtains the system timestamp.

    Return type: timestamp with time zone

    Example:

    MogDB=# SELECT pg_systimestamp();
        pg_systimestamp
-------------------------------
 2015-10-14 11:21:28.317367+08
(1 row)

  • rawtohex(string)

    Description: Converts a string in binary format into hexadecimal format.

    The result is the ACSII code of the input characters in hexadecimal format.

    Return type: varchar

    Example:

    MogDB=# SELECT rawtohex('1234567');
    rawtohex
----------------
 31323334353637
(1 row)

  • to_bigint(varchar)

    Description: Converts the character type to the bigint type.

    Return type: bigint

    Example:

    MogDB=# SELECT to_bigint('123364545554455');
    to_bigint
----------------
 123364545554455
(1 row)

  • to_char (datetime/interval [, fmt])

    Description: Converts a DATETIME or INTERVAL value of the DATE/TIMESTAMP/TIMESTAMP WITH TIME ZONE/TIMESTAMP WITH LOCAL TIME ZONE type into the TEXT type according to the format specified by fmt.

    • The optional parameter fmt allows for the following types: date, time, week, quarter, and century. Each type has a unique template. The templates can be combined together. Common templates include HH, MI, SS, YYYY, MM, and DD.
    • A template may have a modification word. FM is a common modification word and is used to suppress the preceding zero or the following blank spaces.
    • For TIMESTAMP WITH TIME ZONE, you can use TZH, TZM, TZD, TZR parameters in TO_CHAR to output time zone information.

    Return type: TEXT

    Example:

    MogDB=# SELECT to_char(current_timestamp,'HH12:MI:SS');
 to_char
----------
 10:19:26
(1 row)
    MogDB=# SELECT to_char(current_timestamp,'FMHH12:FMMI:FMSS');
 to_char
----------
 10:19:46
(1 row)
    MogDB=# select to_char(systimestamp, 'TZH'); 
to_char
--------- 
+08
(1 row)

MogDB=# select to_char(systimestamp, 'TZM');
to_char
---------
00
(1 row)

MogDB=# select to_char(systimestamp, 'TZD');
to_char
---------
CST
(1 row)

MogDB=# select to_char(systimestamp, 'TZR');
to_char
---------------
Asia/Shanghai
(1 row)

    Table 1 Template Patterns for Date/Time Formatting

    Pattern Description
    HH hour of day (01-12)
    HH12 hour of day (01-12)
    HH24 hour of day (00-23)
    MI minute (00-59)
    SS second (00-59)
    MS millisecond (000-999)
    US microsecond (000000-999999)
    SSSS seconds past midnight (0-86399)
    AM, am, PM or pm meridiem indicator (without periods)
    A.M., a.m., P.M. or p.m. meridiem indicator (with periods)
    Y,YYY year (4 or more digits) with comma
    YYYY year (4 or more digits)
    YYY last 3 digits of year
    YY last 2 digits of year
    Y last digit of year
    IYYY ISO 8601 week-numbering year (4 or more digits)
    IYY last 3 digits of ISO 8601 week-numbering year
    IY last 2 digits of ISO 8601 week-numbering year
    I last digit of ISO 8601 week-numbering year
    BC, bc, AD or ad era indicator (without periods)
    B.C., b.c., A.D. or a.d. era indicator (with periods)
    MONTH full upper case month name (blank-padded to 9 chars)
    Month full capitalized month name (blank-padded to 9 chars)
    month full lower case month name (blank-padded to 9 chars)
    MON abbreviated upper case month name (3 chars in English, localized lengths vary)
    Mon abbreviated capitalized month name (3 chars in English, localized lengths vary)
    mon abbreviated lower case month name (3 chars in English, localized lengths vary)
    MM month number (01-12)
    DAY full upper case day name (blank-padded to 9 chars)
    Day full capitalized day name (blank-padded to 9 chars)
    day full lower case day name (blank-padded to 9 chars)
    DY abbreviated upper case day name (3 chars in English, localized lengths vary)
    Dy abbreviated capitalized day name (3 chars in English, localized lengths vary)
    dy abbreviated lower case day name (3 chars in English, localized lengths vary)
    DDD day of year (001-366)
    IDDD day of ISO 8601 week-numbering year (001-371; day 1 of the year is Monday of the first ISO week)
    DD day of month (01-31)
    D day of the week, Sunday (1) to Saturday (7)
    ID ISO 8601 day of the week, Monday (1) to Sunday (7)
    W week of month (1-5) (the first week starts on the first day of the month)
    WW week number of year (1-53) (the first week starts on the first day of the year)
    IW week number of ISO 8601 week-numbering year (01-53; the first Thursday of the year is in week 1)
    CC century (2 digits) (the twenty-first century starts on 2001-01-01)
    J Julian Day (integer days since November 24, 4714 BC at midnight UTC)
    Q quarter
    RM month in upper case Roman numerals (I-XII; I=January)
    rm month in lower case Roman numerals (i-xii; i=January)
    TZ upper case time-zone abbreviation (only supported in to_char)
    tz lower case time-zone abbreviation (only supported in to_char)
    TZH Time zone hour
    TZM Time zone minute
    TZD Time zone daylight saving time
    TZR Time zone region

  • to_char(double precision/real, text)

    Description: Converts the values of the floating point type into the strings in the specified format.

    Return type: text

    Example:

    MogDB=# SELECT to_char(125.8::real, '999D99');
 to_char
---------
  125.80
(1 row)

  • to_char (numeric/smallint/integer/bigint/double precision/real[, fmt])

    Descriptions: Converts an integer or a value in floating point format into a string in specified format.

    • The optional parameter fmt allows for the following types: decimal characters, grouping characters, positive/negative sign and currency sign. Each type has a unique template. The templates can be combined together. Common templates include: 9, 0, millesimal sign (,), and decimal point (.).
    • A template can have a modification word, similar to FM. However, FM does not suppress 0 which is output according to the template.
    • Use the template X or x to convert an integer value into a string in hexadecimal format.

    Return type: varchar

    Example:

    MogDB=# SELECT to_char(1485,'9,999');
 to_char
---------
  1,485
(1 row)
    MogDB=# SELECT to_char( 1148.5,'9,999.999');
  to_char
------------
  1,148.500
(1 row)
    MogDB=# SELECT to_char(148.5,'990999.909');
   to_char
-------------
    0148.500
(1 row)
    MogDB=# SELECT to_char(123,'XXX');
 to_char
---------
   7B
(1 row)

  • to_char(interval, text)

    Description: Converts the values of the time interval type into the strings in the specified format.

    Return type: text

    Example:

    MogDB=# SELECT to_char(interval '15h 2m 12s', 'HH24:MI:SS');
 to_char
----------
 15:02:12
(1 row)

  • to_char(int, text)

    Description: Converts the values of the integer type into the strings in the specified format.

    Return type: text

    Example:

    MogDB=# SELECT to_char(125, '999');
 to_char
---------
  125
(1 row)

  • to_char(set)

    Description: Converts the values of the SET type into the strings in the specified format.

    Return type: text

    Example:

    - The site column is of the SET type in the employee table.
   
MogDB=# select to_char(site) from employee;
to_char
---------
beijing,nanjing
beijing,wuhan
(2 rows)

  • to_char(numeric, text)

    Description: Converts the values of the numeric type into the strings in the specified format.

    Return type: text

    Example:

    MogDB=# SELECT to_char(-125.8, '999D99S');
 to_char
---------
 125.80-
(1 row)

  • to_char (string)

    Description: Converts the CHAR/VARCHAR/VARCHAR2/CLOB type into the VARCHAR type.

    If this function is used to convert data of the CLOB type, and the value to be converted exceeds the value range of the target type, an error is returned.

    Return type: varchar

    Example:

    MogDB=# SELECT to_char('01110');
 to_char
---------
 01110
(1 row)

  • to_char(timestamp, text)

    Description: Converts the values of the timestamp type into the strings in the specified format.

    Return type: text

    Example:

    MogDB=# SELECT to_char(current_timestamp, 'HH12:MI:SS');
 to_char
----------
 10:55:59
(1 row)

  • to_clob(char/nchar/varchar/varchar2/nvarchar/nvarchar2/text/raw)

    Description: Converts the raw type or text character set type CHAR, NCHAR, VARCHAR, VARCHAR2, NVARCHAR, NVARCHAR2, or TEXT to the CLOB type.

    Return type: clob

    Example:

    MogDB=# SELECT to_clob('ABCDEF'::RAW(10));
 to_clob
---------
 ABCDEF
(1 row)
    MogDB=# SELECT to_clob('hello111'::CHAR(15));
 to_clob
----------
 hello111
(1 row)
    MogDB=# SELECT to_clob('gauss123'::NCHAR(10));
 to_clob
----------
 gauss123
(1 row)
    MogDB=# SELECT to_clob('gauss234'::VARCHAR(10));
 to_clob
----------
 gauss234
(1 row)
    MogDB=# SELECT to_clob('gauss345'::VARCHAR2(10));
 to_clob
----------
 gauss345
(1 row)
    MogDB=# SELECT to_clob('gauss456'::NVARCHAR2(10));
 to_clob
----------
 gauss456
(1 row)
    MogDB=# SELECT to_clob('World222!'::TEXT);
  to_clob
-----------
 World222!
(1 row)

  • to_date(text)

    Description: Converts values of the text type into the timestamp in the specified format. Currently, only the following two formats are supported:

    • Format 1: Date without separators, for example, 20150814. The value must contain the complete year, month, and day.
    • Format 2: Date with separators, for example, 2014-08-14. The separator can be any non-digit character.

    Return type: timestamp without time zone

    Example:

      MogDB=# SELECT to_date('2015-08-14');
         to_date
  ---------------------
   2015-08-14 00:00:00
  (1 row)

  • to_date(text, text)

    Description: Converts the values of the string type into the dates in the specified format.

    Return type: timestamp without time zone

    Example:

    MogDB=# SELECT to_date('05 Dec 2000', 'DD Mon YYYY');
       to_date
---------------------
 2000-12-05 00:00:00
(1 row)

  • to_number ( expr [, fmt])

    Description: Converts expr into a value of the NUMBER type according to the specified format.

    For details about the type conversion formats, see Table 2.

    If a hexadecimal string is converted into a decimal number, the hexadecimal string can include a maximum of 16 bytes if it is to be converted into a sign-free number.

    During the conversion from a hexadecimal string to a decimal digit, the format string cannot have a character other than x or X. Otherwise, an error is reported.

    Return type: number

    Example:

    MogDB=# SELECT to_number('12,454.8-', '99G999D9S');
 to_number
-----------
  -12454.8
(1 row)

  • to_number(text, text)

    Description: Converts the values of the string type into the numbers in the specified format.

    Return type: numeric

    Example:

    MogDB=# SELECT to_number('12,454.8-', '99G999D9S');
 to_number
-----------
  -12454.8
(1 row)

  • to_timestamp(double precision)

    Description: Converts a UNIX century into a timestamp.

    Return type: timestamp with time zone

    Example:

    MogDB=# SELECT to_timestamp(1284352323);
      to_timestamp
------------------------
 2010-09-13 12:32:03+08
(1 row)

  • to_timestamp(string [,fmt])

    Description: Converts a string into a value of the timestamp type according to the format specified by fmt. When fmt is not specified, perform the conversion according to the format specified by nls_timestamp_format.

    In to_timestamp in MogDB,

    • If the input year YYYY is 0, an error will be reported.
    • If the input year YYYY is less than 0, specify SYYYY in fmt. The year with the value of n (an absolute value) BC will be output correctly.

    Characters in the fmt must match the schema for formatting the data and time. Otherwise, an error is reported.

    Return type: timestamp without time zone

    Example:

    MogDB=# SHOW nls_timestamp_format;
    nls_timestamp_format
----------------------------
 DD-Mon-YYYY HH:MI:SS.FF AM
(1 row)

MogDB=# SELECT to_timestamp('12-sep-2014');
    to_timestamp
---------------------
 2014-09-12 00:00:00
(1 row)
    MogDB=# SELECT to_timestamp('12-Sep-10 14:10:10.123000','DD-Mon-YY HH24:MI:SS.FF');
      to_timestamp
-------------------------
 2010-09-12 14:10:10.123
(1 row)
    MogDB=# SELECT to_timestamp('-1','SYYYY');
      to_timestamp
------------------------
 0001-01-01 00:00:00 BC
(1 row)
    MogDB=# SELECT to_timestamp('98','RR');
    to_timestamp
---------------------
 1998-01-01 00:00:00
(1 row)
    MogDB=# SELECT to_timestamp('01','RR');
    to_timestamp
---------------------
 2001-01-01 00:00:00
(1 row)

  • to_timestamp(text, text)

    Description: Converts values of the string type into the timestamp of the specified type.

    Return type: timestamp

    Example:

    MogDB=# SELECT to_timestamp('05 Dec 2000', 'DD Mon YYYY');
    to_timestamp
---------------------
 2000-12-05 00:00:00
(1 row)

Table 2 Template patterns for numeric formatting

Pattern Description
9 Value with specified digits
0 Values with leading zeros
Period (.) Decimal point
Comma (,) Group (thousand) separator
PR Negative values in angle brackets
S Sign anchored to number (uses locale)
L Currency symbol (uses locale)
D Decimal point (uses locale)
G Group separator (uses locale)
MI Minus sign in the specified position (if the number is less than 0)
PL Plus sign in the specified position (if the number is greater than 0)
SG Plus or minus sign in the specified position
RN Roman numerals (the input values are between 1 and 3999)
TH or th Ordinal number suffix
V Shifts specified number of digits (decimal)

  • abstime_text

    Description: Converts abstime to text.

    Parameter: abstime

    Return type: text

  • abstime_to_smalldatetime

    Description: Converts abstime to smalldatatime.

    Parameter: abstime

    Return type: smalldatetime

  • bigint_tid

    Description: Converts bigint to tid.

    Parameter: bigint

    Return type: tid

  • bool_int1

    Description: Converts bool to int1.

    Parameter: Boolean

    Return type: tinyint

  • bool_int2

    Description: Converts bool to int2.

    Parameter: Boolean

    Return type: smallint

  • bool_int8

    Description: Converts bool to int8.

    Parameter: Boolean

    Return type: bigint

  • bpchar_date

    Description: Converts a string to a date.

    Parameter: character

    Return type: date

  • bpchar_float4

    Description: Converts a string to float4.

    Parameter: character

    Return type: real

  • bpchar_float8

    Description: Converts a string to float8.

    Parameter: character

    Return type: double precision

  • bpchar_int4

    Description: Converts a string to int4.

    Parameter: character

    Return type: integer

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