Oracle SQL Developer

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Storing Numeric Data■■NCHAR and NVARCHAR2 data types store variable-length Unicode character dataonly.CHAR and NCHAR data types store fixed-length character literals.5.2.2 Choosing Between the Character Data TypesWhen deciding which data type to use for a column that will store alphanumeric datain a table, consider the following points of distinction:■■■5.3 Storing Numeric DataSpace usageTo store data more efficiently, use the VARCHAR2 data type. The CHAR data typeblank-pads and stores trailing blanks up to a fixed column length for all columnvalues, whereas the VARCHAR2 data type does not add extra blanks.Comparison semanticsUse the CHAR data type when you require ANSI compatibility in comparisonsemantics (when trailing blanks are not important in string comparisons). Use theVARCHAR2 when trailing blanks are important in string comparisons.Future compatibilityThe CHAR and VARCHAR2 data types are fully supported.This topic contains the following topics:■■■What Are the Numeric Data Types?Using NUMBER Data TypesUsing Floating-Point Number Formats5.3.1 What Are the Numeric Data Types?The following SQL data types store numeric data:■■NUMBERSee Also:■■BINARY_FLOATOracle Database SQL Reference for information on data typesOracle Database Globalization Support Guide for information onglobalization supportSee Also: Oracle Database SQL Reference for more information oncomparison semantics for these data types■ BINARY_DOUBLEUse the NUMBER data type to store integers and real numbers in a fixed-point orfloating-point format. Numbers using this data type are guaranteed to be portableamong different Oracle Database platforms. For nearly all cases where you need tostore numeric data, you would use the NUMBER data type.Oracle Database provides the numeric BINARY_FLOAT and BINARY_DOUBLE datatypes exclusively for floating-point numbers. They support all of the basicfunctionality provided by the NUMBER data type. However, while NUMBER uses5-2 SQL Developer Online Help
Storing Numeric Datadecimal precision, BINARY_FLOAT and BINARY_DOUBLE use binary precision. Thisenables faster arithmetic calculations and usually reduces storage requirements.See Also:■■Oracle Database Concepts for information about the internal formatfor the NUMBER data typeOracle Database SQL Reference for more information about theNUMBER, BINARY_FLOAT, and BINARY_DOUBLE data typesformats5.3.2 Using NUMBER Data TypesThe NUMBER data type stores zero as well as positive and negative fixed numbers withabsolute values from 1.0 x 10 -130 to (but not including) 1.0 x 10 126 . If you specify anarithmetic expression whose value has an absolute value greater than or equal to 1.0 x10 126 , then Oracle returns an error. Each NUMBER value requires from 1 to 22 bytes.When you specify a fixed-point number use the following form to specify the precisionand scale of the number:NUMBER(precision, scale)Precision and scale are defined as follows:■ Precision is the total number of significant decimal digits, where the mostsignificant digit is the left-most nonzero digit, and the least significant digit is theright-most known digit. For examples, see Table 5–1 on page 5-4.■ Scale is the number of digits from the decimal point to the least significant digit.The scale can range from -84 to 127. For examples, see Table 5–1 on page 5-4.– Positive scale is the number of significant digits to the right of the decimalpoint to and including the least significant digit.– Negative scale is the number of significant digits to the left of the decimalpoint, to but not including the least significant digit. For negative scale theleast significant digit is on the left side of the decimal point, because the actualdata is rounded to the specified number of places to the left of the decimalpoint. For example, a specification of (10,-2) means to round to hundreds.Scale can be greater than precision, most commonly when e notation is used. Whenscale is greater than precision, the precision specifies the maximum number ofsignificant digits to the right of the decimal point. For example, a column defined asNUMBER(4,5) requires a zero for the first digit after the decimal point and rounds allvalues past the fifth digit after the decimal point.It is good practice to specify the scale and precision of a fixed-point number columnfor extra integrity checking on input. Specifying scale and precision does not force allvalues to a fixed length. If a value exceeds the precision, then Oracle returns an error. Ifa value exceeds the scale, then Oracle rounds it.Specify an integer using the following form:NUMBER(p)This represents a fixed-point number with precision p and scale 0 and is equivalent toNUMBER(p,0).Specify a floating-point number using the following form:NUMBERData Types: Usage Information 5-3
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Oracle SQL DeveloperOnline HelpRele
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Contents1 SQL Developer Concepts an
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3.12 Create/Edit Index ............
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6.3.2 Updating Data With the UPDATE
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10.2.5 SQL*Plus SET Commands.......
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SQL Developer User InterfaceThe men
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SQL Developer User InterfaceThe Com
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Database Objects1.2 Database Object
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Database Objectscontaining the mast
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Database Objects■■■■■■
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Database ConnectionsWhen you start
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Running and Debugging Functions and
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Using the SQL WorksheetRelated Topi
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Using the SQL WorksheetScript Runne
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Using the SQL Worksheetmentioned in
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Reports1.9 ReportsRelated TopicsRun
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Reports1.9.3 Table reportsTable rep
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Reportsissues and vulnerabilities,
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SQL Developer Preferencesand the SQ
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SQL Developer Preferences1.10.3 Cod
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SQL Developer PreferencesSQL Develo
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SQL Developer User Information: Loc
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Supplementary Oracle Database Infor
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Creating a Table (Books)the table t
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Creating a Table (Transactions)Colu
Page 52 and 53: Creating a SequenceName: for_key_bo
Page 54 and 55: Creating a PL/SQL Procedure2.6 Crea
Page 56 and 57: Using the SQL Worksheet for Queries
Page 58 and 59: Script for Creating and Using the L
Page 60 and 61: Script for Creating and Using the L
Page 62 and 63: Check for UpdatesTo remove the effe
Page 64 and 65: Select Library3.8 Select LibraryThi
Page 66 and 67: Create PL/SQL Function, Procedure,
Page 68 and 69: Create Table (quick creation)Relate
Page 70 and 71: Create/Edit Table (with advanced op
Page 78 and 79: Create Type (User-Defined)For more
Page 80 and 81: Create/Edit ViewTest Syntax: Checks
Page 82 and 83: Configure File Type AssociationsDia
Page 84 and 85: Find/Replace TextTo add a type of o
Page 86 and 87: Save/Save As3.37 Save/Save As3.38 S
Page 88 and 89: SQL*Plus Location3-28 SQL Developer
Page 90 and 91: Managing TablesTo include lowercase
Page 92 and 93: Managing Tables4.2.4 Column Constra
Page 94 and 95: Managing Indexes4.3 Managing Indexe
Page 96 and 97: Managing Indexesuseful when all of
Page 98 and 99: Managing Views4.4 Managing Views4.3
Page 100 and 101: Managing Synonyms4-12 SQL Developer
Page 104 and 105: Storing Numeric DataThe absence of
Page 106 and 107: Storing Datetime Data5.4.1.2 Using
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Page 110 and 111: Retrieving Data With Queries■■
Page 112 and 113: Retrieving Data With QueriesSee Als
Page 114 and 115: Retrieving Data With QueriesSee Als
Page 116 and 117: Transaction Control Statements6.3.2
Page 118 and 119: Using Pseudocolumns, Sequences, and
Page 124 and 125: Using SQL Data Definition Language
Page 126 and 127: Using SQL Data Definition Language
Page 128 and 129: Entering and Executing PL/SQL CodeY
Page 130 and 131: Utilizing the Main Features of PL/S
Page 148 and 149: Handling PL/SQL ErrorsTo handle une
Page 150 and 151: Handling PL/SQL ErrorsIf you redecl
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Handling PL/SQL Errors7-26 SQL Deve
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Overview of Packages and Subprogram
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Managing Packagescalling procedures
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Oracle Product-Specific PackagesTab
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Oracle Product-Specific PackagesTab
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Oracle Product-Specific Packages8-1
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Overview of Triggers9.1.1 Types of
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Overview of Triggers■■A trigger
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Designing TriggersNote: A procedure
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Using SQL*Plus■■■Running Scri
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Using SQL*PlusA SQL script file is
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Using SQL*Plus10-6 SQL Developer On
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Overview of Globalization Support
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Setting up the Globalization Suppor
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SQL and PL/SQL Programming with Uni
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SQL and PL/SQL Programming with Uni
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Locale-Dependent SQL Functions with
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Locale-Dependent SQL Functions with
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COLLECTION_IS_NULL exception, 7-22c
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overview, 7-14EXPLAIN PLANexecution
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NLSSORT SQL function, 11-21NO_DATA_
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displaying output from PL/SQL, 7-9s
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disabling, 9-4enabling, 9-4error co
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Oracle SQL Developer

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