Oracle SQL - Data Types

What is SQL?

Structured Query Language (SQL) is a domain-specific programming language designed to manage the data stored in relational database management system.

SQL Data Types

String Data Type

• CHAR(n) : fixed-length character string / max 2000 bytes / 1 byte default
• VARCHAR2(n) : variable-length character string / max 4000 bytes / 1 byte default
• NCHAR(n) : fixed-length unicode string (can type foreign lang) / max 2000 bytes / 1 byte default
• NVARCHAR(n) : variable-length unicode string (can type foreign lang) / max 2000 bytes / 1 byte default
• LONG : variable-length string with max 2GB size
• CLOB : large-size text data type / max 4GB
• NCLOB : large-size text unicode data type / max 4GB

Number Data Type

• NUMBER(P, S) : variable-length number / P (1 - 38, Default : 38) , S (-84 - 127, Default : 0) / max 22 bytes
• FLOAT(P) : subtype of NUMBER / P (1 - 128, Default : 128) / max 22 bytes
• BINARY_FLOAT : 32-bit single-precision floating-point number datatype
• BINARY_DOUBLE : 64-bit double-precision floating-point number datatype

Date Data Type

• DATE : valid date range from January/01/4712 BC to December/31/9999 AD
• TIMESTAMP : prints date including year, month, day values of date, hour, minute, and second values of time