Type Conversion Functions
Type Conversion Functions
cash_words(money)
Description: Type conversion function, which converts money into text.
Example:
openGauss=# 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:
openGauss=# 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 raw type.
Return type: raw
Example:
openGauss=# 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:
openGauss=# SELECT numtoday(2); numtoday ---------- 2 days (1 row)pg_systimestamp()
Description: Obtains the system timestamp.
Return type: timestamp with time zone
Example:
openGauss=# 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:
openGauss=# SELECT rawtohex('1234567'); rawtohex ---------------- 31323334353637 (1 row)to_bigint(varchar)
Description: Converts the character type to the bigint type.
Return type: bigint
Example:
openGauss=# 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.
Return type: text
Example:
openGauss=# SELECT to_char(current_timestamp,'HH12:MI:SS'); to_char ---------- 10:19:26 (1 row)openGauss=# SELECT to_char(current_timestamp,'FMHH12:FMMI:FMSS'); to_char ---------- 10:19:46 (1 row)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:
openGauss=# 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:
openGauss=# SELECT to_char(1485,'9,999'); to_char --------- 1,485 (1 row)openGauss=# SELECT to_char( 1148.5,'9,999.999'); to_char ------------ 1,148.500 (1 row)openGauss=# SELECT to_char(148.5,'990999.909'); to_char ------------- 0148.500 (1 row)openGauss=# 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:
openGauss=# 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:
openGauss=# 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. openGauss=# 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:
openGauss=# 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:
openGauss=# 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:
openGauss=# 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:
openGauss=# SELECT to_clob('ABCDEF'::RAW(10)); to_clob --------- ABCDEF (1 row)openGauss=# SELECT to_clob('hello111'::CHAR(15)); to_clob ---------- hello111 (1 row)openGauss=# SELECT to_clob('gauss123'::NCHAR(10)); to_clob ---------- gauss123 (1 row)openGauss=# SELECT to_clob('gauss234'::VARCHAR(10)); to_clob ---------- gauss234 (1 row)openGauss=# SELECT to_clob('gauss345'::VARCHAR2(10)); to_clob ---------- gauss345 (1 row)openGauss=# SELECT to_clob('gauss456'::NVARCHAR2(10)); to_clob ---------- gauss456 (1 row)openGauss=# 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:
openGauss=# 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:
openGauss=# 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 1.
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:
openGauss=# 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:
openGauss=# 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:
openGauss=# 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 openGauss,
- 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:
openGauss=# SHOW nls_timestamp_format; nls_timestamp_format ---------------------------- DD-Mon-YYYY HH:MI:SS.FF AM (1 row) openGauss=# SELECT to_timestamp('12-sep-2014'); to_timestamp --------------------- 2014-09-12 00:00:00 (1 row)openGauss=# 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)openGauss=# SELECT to_timestamp('-1','SYYYY'); to_timestamp ------------------------ 0001-01-01 00:00:00 BC (1 row)openGauss=# SELECT to_timestamp('98','RR'); to_timestamp --------------------- 1998-01-01 00:00:00 (1 row)openGauss=# 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:
openGauss=# SELECT to_timestamp('05 Dec 2000', 'DD Mon YYYY'); to_timestamp --------------------- 2000-12-05 00:00:00 (1 row)
Table 1 Template patterns for numeric formatting
Minus sign in the specified position (if the number is less than 0) | |
Plus sign in the specified position (if the number is greater than 0) | |
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
bpchar_int8
Description: Converts a string to int8.
Parameter: character
Return type: bigint
bpchar_numeric
Description: Converts a string to numeric.
Parameter: character
Return type: numeric
bpchar_timestamp
Description: Converts a string to a timestamp.
Parameter: character
Return type: timestamp without time zone
bpchar_to_smalldatetime
Description: Converts a string to smalldatetime.
Parameter: character
Return type: smalldatetime
cupointer_bigint
Description: Converts the column-store CU pointer type to the bigint type.
Parameter: text
Return type: bigint
date_bpchar
Description: Converts the date type to bpchar.
Parameter: date
Return type: character
date_text
Description: Converts date to text.
Parameter: date
Return type: text
date_varchar
Description: Converts date to varchar.
Parameter: date
Return type: character varying
f4toi1
Description: Forcibly converts float4 to uint8.
Parameter: real
Return type: tinyint
f8toi1
Description: Forcibly converts float8 to uint8.
Parameter: double precision
Return type: tinyint
float4_bpchar
Description: Converts float4 to bpchar.
Parameter: real
Return type: character
float4_text
Description: Converts float4 to text.
Parameter: real
Return type: text
float4_varchar
Description: Converts float4 to varchar.
Parameter: real
Return type: character varying
float8_bpchar
Description: Converts float8 to bpchar.
Parameter: double precision
Return type: character
float8_interval
Description: Converts float8 to interval.
Parameter: double precision
Return type: interval
float8_text
Description: Converts float8 to text.
Parameter: double precision
Return type: text
float8_varchar
Description: Converts float8 to varchar.
Parameter: double precision
Return type: character varying
i1tof4
Description: Converts uint8 to float4.
Parameter: tinyint
Return type: real
i1tof8
Description: Converts uint8 to float8.
Parameter: tinyint
Return type: double precision
i1toi2
Description: Converts uint8 to int16.
Parameter: tinyint
Return type: smallint
i1toi4
Description: Converts uint8 to int32.
Parameter: tinyint
Return type: integer
i1toi8
Description: Converts uint8 to int64.
Parameter: tinyint
Return type: bigint
i2toi1
Description: Converts int16 to uint8.
Parameter: smallint
Return type: tinyint
i4toi1
Description: Converts int32 to uint8.
Parameter: integer
Return type: tinyint
i8toi1
Description: Converts int64 to uint8.
Parameter: bigint
Return type: tinyint
int1_avg_accum
Description: Adds the second parameter of the uint8 type to the first parameter. The first parameter is an array of the bigint type.
Parameter: bigint[], tinyint
Return type: bigint[]
int1_bool
Description: Converts uint8 to bool.
Parameter: tinyint
Return type: Boolean
int1_bpchar
Description: Converts uint8 to bpchar.
Parameter: tinyint
Return type: character
int1_mul_cash
Description: Returns the product of a parameter of the int8 type and a parameter of the cash type. The return type is cash.
Parameter: tinyint, money
Return type: money
int1_numeric
Description: Converts uint8 to numeric.
Parameter: tinyint
Return type: numeric
int1_nvarchar2
Description: Converts uint8 to nvarchar2.
Parameter: tinyint
Return type: nvarchar2
int1_text
Description: Converts uint8 to text.
Parameter: tinyint
Return type: text
int1_varchar
Description: Converts uint8 to varchar.
Parameter: tinyint
Return type: character varying
int1in
Description: Converts a string into an unsigned 1-byte integer.
Parameter: cstring
Return type: tinyint
int1out
Description: Converts an unsigned 1-byte integer into a string.
Parameter: tinyint
Return type: cstring
int1up
Description: Converts an input integer to an unsigned 1-byte integer.
Parameter: tinyint
Return type: tinyint
int2_bool
Description: Converts a signed two-byte integer to the bool type.
Parameter: smallint
Return type: Boolean
int2_bpchar
Description: Converts a signed two-byte integer to the bpchar type.
Parameter: smallint
Return type: character
int2_text
Description: Converts a signed two-byte integer to the text type.
Parameter: smallint
Return type: text
int2_varchar
Description: Converts a signed two-byte integer to the varchar type.
Parameter: smallint
Return type: character varying
int8_text
Description: Converts an eight-byte signed integer to the text type.
Parameter: bigint
Return type: text
int8_varchar
Description: Converts an eight-byte signed integer to varchar.
Parameter: bigint
Return type: character varying
intervaltonum
Description: Converts the internal dats type date to numeric.
Parameter: interval
Return type: numeric
numeric_bpchar
Description: Converts numeric to bpchar.
Parameter: numeric
Return type: character
numeric_int1
Description: Converts numeric to a signed one-byte integer.
Parameter: numeric
Return type: tinyint
numeric_text
Description: Converts numeric to text.
Parameter: numeric
Return type: text
numeric_varchar
Description: Converts numeric to varchar.
Parameter: numeric
Return type: character varying
nvarchar2in
Description: Converts c string to varchar.
Parameter: cstring, oid, integer
Return type: nvarchar2
nvarchar2out
Description: Converts text into a c string.
Parameter: nvarchar2
Return type: cstring
nvarchar2send
Description: Converts varchar to binary.
Parameter: nvarchar2
Return type: bytea
oidvectorin_extend
Description: Converts a string to oidvector.
Parameter: cstring
Return type: oidvector_extend
oidvectorout_extend
Description: Converts oidvector to a string.
Parameter: oidvector_extend
Return type: cstring
oidvectorsend_extend
Description: Converts oidvector to a string.
Parameter: oidvector_extend
Return type: bytea
reltime_text
Description: Converts reltime to text.
Parameter: reltime
Return type: text
text_date
Description: Converts the text type to the date type.
Parameter: text
Return type: date
text_float4
Description: Converts text to float4.
Parameter: text
Return type: real
text_float8
Description: Converts the text type to float8.
Parameter: text
Return type: double precision
text_int1
Description: Converts the text type to int1.
Parameter: text
Return type: tinyint
text_int2
Description: Converts the text type to the int2 type.
Parameter: text
Return type: smallint
text_int4
Description: Converts the text type to int4.
Parameter: text
Return type: integer
text_int8
Description: Converts the text type to the int8 type.
Parameter: text
Return type: bigint
text_numeric
Description: Converts the text type to the numeric type.
Parameter: text
Return type: numeric
text_timestamp
Description: Converts the text type to the timestamp type.
Parameter: text
Return type: timestamp without time zone
time_text
Description: Converts the time type to the text type.
Parameter: time without time zone
Return type: text
timestamp_text
Description: Converts the timestamp type to the text type.
Parameter: timestamp without time zone
Return type: text
timestamp_to_smalldatetime
Description: Converts the timestamp type to the smalldatetime type.
Parameter: timestamp without time zone
Return type: smalldatetime
timestamp_varchar
Description: Converts the timestamp type to varchar.
Parameter: timestamp without time zone
Return type: character varying
timestamptz_to_smalldatetime
Description: Converts timestamptz to smalldatetime.
Parameter: timestamp with time zone
Return type: smalldatetime
timestampzone_text
Description: Converts the timestampzone type to the text type.
Parameter: timestamp with time zone
Return type: text
timetz_text
Description: Converts the timetz type to the text type.
Parameter: time with time zone
Return type: text
to_integer
Description: Converts data to the integer type.
Parameter: character varying
Return type: integer
to_interval
Description: Converts to the interval type.
Parameter: character varying
Return type: interval
to_numeric
Description: Converts to the numeric type.
Parameter: character varying
Return type: numeric
to_nvarchar2
Description: Converts to the nvarchar2 type.
Parameter: numeric
Return type: nvarchar2
to_text
Description: Converts to the text type.
Parameter: smallint
Return type: text
to_ts
Description: Converts to the ts type.
Parameter: character varying
Return type: timestamp without time zone
to_varchar2
Description: Converts to the varchar2 type.
Parameter: timestamp without time zone
Return type: character varying
varchar_date
Description: Converts varchar to date.
Parameter: character varying
Return type: date
varchar_float4
Description: Converts varchar to float4.
Parameter: character varying
Return type: real
varchar_float8
Description: Converts the varchar type to the float8 type.
Parameter: character varying
Return type: double precision
varchar_int4
Description: Converts the type from varchar to int4.
Parameter: character varying
Return type: integer
varchar_int8
Description: Converts the varchar type to the int8 type.
Parameter: character varying
Return type: bigint
varchar_numeric
Description: Converts varchar to numeric.
Parameter: character varying
Return type: numeric
varchar_timestamp
Description: Converts varchar to timestamp.
Parameter: character varying
Return type: timestamp without time zone
varchar2_to_smlldatetime
Description: Converts varchar2 to smlldatetime.
Parameter: character varying
Return type: smalldatetime
xidout4
Description: The xid output is a four-byte number.
Parameter: xid32
Return type: cstring
xidsend4
Description: Converts xid to the binary format.
Parameter: xid32
Return type: bytea
Encoding Type Conversion
convert_to_nocase(text, text)
Description: Converts a string into a specified encoding type.
Return type: bytea
Example:
openGauss=# SELECT convert_to_nocase('12345', 'GBK'); convert_to_nocase ------------------- \x3132333435 (1 row)