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Session6 Data type in Oracle

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Session 6: Datatypes In Oracle   ALPHABET           : A-Z , a-z NUMBER              : 0-9 (with precision and scale) DATE / Temporal  : any Date and time (Hours, Minutes, Seconds, Mili-seconds, Timestamp, Timezone etc)   Alphabet + Number = Alphanumeric Data                                     = String / CHARACTER Datatype Category Number                    =  Numeric Datatype Category Date                         = Date Datatype Category 1. CHARACTER Datatype: CHAR, VARCHAR, NCHAR: CHAR is fixed length datatype and VARCHAR is Variable length datatype to store character data. i.e. A-Z , a-z , 0-9 , all keyboard characters etc. The default size is 1 character and it can store maximum up to 2000 bytes. Example : EName, EmpID, PassportNo, SSN, etc. EName CHAR(10) := ‘TOM’; wastage of 7 space after the string EName VARCHAR(10) := ‘TOM’; Spaces can be Reuse which left after the string NCHAR additionally handles NLS(National Language Support). Oracle supports a reliable Unicode datatype through NCHAR , NVARCHAR2 , and NCLOB  VARCHAR2, NVARCHAR2: These are Variable length datatype. VARCHAR2 handles alphanumeric character string whereas NVARCHAR2 handles alphanumeric character string with NLS(National Language Support). The default size is 1 character and it can store maximum up to 4000 bytes.   LONG:  Variable length string.  (Maximum size: 2 GB - 1) Only one LONG column is allowed per table. RAW:    Variable length binary string (Maximum size 2000 bytes) LONG RAW: Variable length binary string (Maximum size 2GB) 2. NUMERIC Datatype: NUMBER: It stores Numeric values and performs numeric calculations. NUMBER,   NUMBER(n),   NUMBER(p,s) It stores Numbers up to 38 digits of precision. SeqNo NUMBER;                     1, 123, 12345678 EmpID NUMBER(4);                 1, 123, 1234 Sal NUMBER(7,2);                     23456.78 , 123.45 — correction in video: Sal NUMBER(a7,2); which is wrong please ignore. 1234567 can be a type of NUMBER, NUMBER(7), NUMBER(7,0) It can store both integer and floating point numbers NUMERIC(p,s) FLOAT:   Ex:  EmpSal FLOAT;    FLOAT(7)       Decimal Points allowed DEC(p,s), DECIMAL(p,s) , REAL, DOUBLE PRECISION INTEGER:   Ex:  SSN INTEGER;       Decimal Points are not allowed INT, SMALLINT 3. DATE Datatype: DATE: It stores DATE(Date, Month, Year) and Time(Hour, Minute, Second, AM/PM) and performs calculations with such data. Default DATE format in Oracle is “DD-MON-YY” Based on "Gregorian calendar" where the date ranges from “JAN 1 4712 BC” to “DEC 31 9999 AD” doj DATE;    “18-MAR-2010 12:30:00 PM” TIMESTAMP:    It can store all parameters as DATE datatype and additionally it can have “Fraction of seconds” and TIMESTAMP WITH TIMEZONE / TIMESTAMP WITHOUT TIMEZONE. Range from 0-9 digits, the default size is 6. 4. LOB Datatype: LOB: “Large Object” data. It can store pictures, motion pictures, Textfiles etc. CLOB: “Character Large Object” is used to store structured information like a text file with a specific file format. BLOB: “Binary Large Object” is used to store Un-structured information like Image, JPEG files, MPEG files etc. BFILE: “Binary File” is used to store the pointer to a specific file / Just store the location of a file. Maximum size: (4 GB - 1) * DB_BLOCK_SIZE initialization parameter (8 TB to 128 TB) Extra Information: NCLOB : It supports all the character set supported by CLOB and additionally it handles NLS(National Language Support ) Maximum size: (4 GB - 1) * DB_BLOCK_SIZE initialization parameter (8 TB to 128 TB) ROWID and UROWID(optional size) Datatype: contains fixed length Binary data. BBBBBBB.RRRR.FFFFF combination of BLOCK-ROW-DATABASE FILE Physical and Logical ROWID Upcoming Session: Session 7: Populating Data into Tables(INSERT Statement): Inserting data into all columns of a table Inserting data into Required columns of a table Inserting NULL value into a table Inserting Special Values(USER / SYSDATE) into a table Supplying data at runtime(using & and &&) THANK YOU :)
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Text Comments (1)
Rajkishor Mahanada (1 month ago)
If you just define a column as NUMBER without giving it a length , what would be the default behavior ? thanks and keep up the great work.Really enjoyed your vedios .

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