Postgresql中的dataType 1.整数类型 smallint(int2) 2bytes integer(int,int4) 4bytes bigint(int8) 8bytes 2.任意精度数值 numeric(precision,scale),用于精确的货币和科学计算。 eg:23.5141,precision=6,scale-4 如果指定,precision最大值为1000,如果numeric中没有指定precious,小数点前最多有131072个数字,小数...
PostgreSQL has a rich set of native data types available to users. Users can add new types to PostgreSQL using the CREATE TYPE command. PostgreSQL有一组丰富的本地数据类型可供用户使用。用户可以使用CREATE TYPE命令向PostgreSQL添加新类型。Each data type has an external representation determined by its...
Postgresql:内置数据类型(data type) sql standard sqlserver postgresql postgresqlaliases description bigint bigint bigint int8 signed eight-byte integer:有符号8字节整数 bigserial serial8 autoincrementing eight-byte integer:自增属性的 bigint bit binary bit [ (n) ] fixed-length ...
所以只有一种可能:Ndom语言的数字是6进制。所以mer为6,thef为2,nif是mer的平方即36,...
Postgresql:内置数据类型(data type), sqlstandardsqlserverpostgresqlpostgresqlaliasesdescription bigintbigintbigintint8signedeight-byteinteger:有符号8字节整数
CAST ( expr AS data_type )函数用于将 expr 转换为 data_type 数据类型;PostgreSQL类型转换运算符(::)也可以实现相同的功能。例如: SELECTCAST('15'ASINTEGER),'2020-03-15'::DATE;int4|date|---|---|15|2020-03-15| 如果数据无法转换为指定的类型,将会返回错误: SELECTCAST('...
PostgreSQL - Data Type PostgreSQL - Data TypeNumeric TypesMonetary TypesCharacter TypesDate/Time TypesBoolean TypeEnumerated TypeGeomertic TypeNetwork Address TypeBit String TypeUUID TypeXML TypeJS...
AGGREGATE agg_name (agg_type) | CAST (source_type AS target_type) | CONSTRAINT constraint_name ON table_name | CONVERSION object_name | DATABASE object_name | DOMAIN object_name | FUNCTION func_name (arg1_type, arg2_type, ...) | ...
select col.table_schema, col.table_name, col.ordinal_position, col.column_name, col.data_type, col.character_maximum_length, col.numeric_precision, col.numeric_scale, col.is_nullable, col.column_default, des.description from information_schema.columns col left join pg_description des on col....
This document discusses PostgreSQL Data Types. While creating table, for each column, you specify a data type, i.e. what kind of data you want to store.