Case Sensitivity Issues in Primary Keys - Oracle to SQL Server Migration (2024)

FAQs

How to avoid case sensitive in Oracle? ›

Use regular expressions. From Oracle 10g onwards REGEXP_LIKE() is available. You can specify the _match_parameter_ 'i' , in order to perform case-insensitive searching. In order to use this as an equality operator you must specify the start and end of the string, which is denoted by the carat and the dollar sign.

In SQL Server, by default, primary keys are case-insensitive and when you transfer data from Oracle to SQL Server and then try to create the primary key constraints, you may have duplicate key errors.

To do a case-insensitive comparison, use the ILIKE keyword; e.g., column ILIKE 'aBc' and column ILIKE 'ABC' both return TRUE for 'abc' . In contrast, MySQL and MS SQL Server have case-insensitive behaviors by default. This means WHERE column = 'abc' returns TRUE for e.g., 'abc' , 'ABC' , or 'aBc' .

Conclusion. To recap, the grep command allows you to search for a pattern inside of files, and is case sensitive by default. To make grep case insensitive, all you have to do is add an -i or —ignore-case flag.

You can turn off table name case sensitivity in MySQL by setting the parameter lower_case_table_names to 1. Column, index, stored routine, event names, and column aliases aren't case sensitive on either platform.

Object name case sensitivity is different for Oracle and PostgreSQL. Oracle names aren't case sensitive. PostgreSQL names are case sensitive.

Case insensitive SQL SELECT: Use upper or lower functions

or this: select * from users where lower(first_name) = 'fred'; As you can see, the pattern is to make the field you're searching into uppercase or lowercase, and then make your search string also be uppercase or lowercase to match the SQL function you've used.

PL/SQL keywords are not case-sensitive, so lower-case letters are equivalent to corresponding upper-case letters except within string and character literals.

SQL Server is, by default, case insensitive; however, it is possible to create a case-sensitive SQL Server database and even to make specific table columns case sensitive. The way to determine if a database or database object is to check its "COLLATION" property and look for "CI" or "CS" in the result.

What is the best choice for primary key SQL Server? ›

Integer (number) data types are the best choice for primary key, followed by fixed-length character data types. SQL Server processes number data type values faster than character data type values because it converts characters to ASCII equivalent values before processing, which is an extra step.

To write a case-sensitive search in SQL Server, don't use UPPER or LOWER functions around the column to filter. Instead, use the COLLATE keyword with a case-sensitive collation followed by the comparison.

You can also make column case sensitive by changing column's collation from case insensitive SQL_Latin1_General_CP1_CI_AI to case sensitive Latin1_General_CS_AS. Lets use Alter Command to change the column Name collation from case insensitive to case sensitive.

MS SQL Server

The column names in a select statement are not case sensitive even if quoted.

Since the replace() function search is case sensitive, it will not consider 'Sql' the same as 'SQL.

In computers, case sensitivity defines whether uppercase and lowercase letters are treated as distinct (case-sensitive) or equivalent (case-insensitive). For instance, when users interested in learning about dogs search an e-book, "dog" and "Dog" are of the same significance to them.

Anything that is not case-sensitive means that any uppercase or lowercase character can be entered. For example, the Windows command line or MS-DOS is not case-sensitive, however, the Linux command line is case-sensitive.

A case sensitive programming language means that the program will treat the uppercase and lowercase letters differently. Hence, we must use the exact case according to the syntax because changing the case, for example from print to Print, will result in an error.

Although database, table, and trigger names are not case-sensitive on some platforms, you should not refer to one of these using different cases within the same statement.

By default, delimited identifiers are not case sensitive. To comply with ANSI/ISO Entry SQL-92, however, delimited identifiers must be case sensitive. The DBMS Server treats database, user, group, role, cursor, and location names without regard to case. Mixed-case database or location names cannot be created.

How do I make a data validation list case sensitive? ›

By default, Oracle identifiers (table names, column names, etc.) are case-insensitive. You can make them case-sensitive by using quotes around them (eg: SELECT * FROM "My_Table" WHERE "my_field" = 1 ). SQL keywords ( SELECT , WHERE , JOIN , etc.)

Starting with Oracle Database 10g Release 2 you can use the initialization parameters NLS_COMP and NLS_SORT to render all string comparisons case insensitive. We need to set the NLS_COMP parameter to LINGUISTIC, which will tell the database to use NLS_SORT for string comparisons.

Names are not case sensitive. A name must begin with an alphabetic character from your database character set unless surrounded by double quotation marks.

The SQL keywords (SELECT, FROM, WHERE, etc.) are case-insensitive, yet they are frequently expressed in all capitals. Table and column names are case-sensitive in some settings.

Question: What is Alternative to CASE Statement in SQL Server? Answer: IIF Function.

LCASE or LOWER takes a character expression as a parameter and returns a string in which all alpha characters have been converted to lowercase.

SQL Server LOWER() Function

The LOWER() function converts a string to lower-case.

Primary keys must contain UNIQUE values, and cannot contain NULL values. A table can have only ONE primary key; and in the table, this primary key can consist of single or multiple columns (fields).

Is primary key always unique in SQL Server? ›

If a primary key consists of more than one column, duplicate values are allowed in one column, but each combination of values from all the columns in the primary key must be unique.

By default, SQL Server names are case insensitive. However, you can create a case sensitive SQL Server database by changing the COLLATION property. In PostgreSQL, object names are case insensitive. By default, the AWS Schema Conversion Tool (AWS SCT) uses object names in lowercase for PostgreSQL.

CASE STATEMENT IN WHERE CLAUSE:

We can use a case statement in Where, Order by and Group by clause. In the Customer table, I have displayed the First Name is Ram or the Last Name is Sharma's salary. So, by using a CASE statement with the where condition displays the result.

By default, table aliases are case sensitive. You can specify an alias in any lettercase (upper, lower, or mixed), but if you use it multiple times in a statement, you must use the same lettercase each time.

Most databases treat table column names as case-insensitive. However, some databases, for example Sybase, treat table column names as case-sensitive.

Database, table, table aliases and trigger names are affected by the systems case-sensitivity, while index, column, column aliases, stored routine and event names are never case sensitive. Log file group name are case sensitive.

In summary, comparisons are case sensitive if they involve a binary literal string or string expression, or a CHAR BINARY , VARCHAR BINARY , or BLOB column. Comparisons are not case sensitive if they involve only non-binary literal strings or string expressions, or CHAR , VARCHAR , ENUM , SET , or TEXT columns.

Starting with Oracle Database 10g Release 2 you can use the initialization parameters NLS_COMP and NLS_SORT to render all string comparisons case insensitive. We need to set the NLS_COMP parameter to LINGUISTIC, which will tell the database to use NLS_SORT for string comparisons.

How to avoid special characters in Oracle? ›

Use braces to escape a string of characters or symbols. Everything within a set of braces in considered part of the escape sequence. When you use braces to escape a single character, the escaped character becomes a separate token in the query. Use the backslash character to escape a single character or symbol.

Oracle names aren't case sensitive.

By default, Oracle identifiers (table names, column names, etc.) are case-insensitive. You can make them case-sensitive by using quotes around them (eg: SELECT * FROM "My_Table" WHERE "my_field" = 1 ). SQL keywords ( SELECT , WHERE , JOIN , etc.)

=~ (equals) operator

Filters a record set for data with a case-insensitive string. For more information about other operators and to determine which operator is most appropriate for your query, see datatype string operators.

B Handling Special Characters

Oracle recommends that you enclose parameter and value pairs in double quotation marks. These special characters must be escaped using double quotation marks (") around the special character or around the parameter value containing the special character.

The Oracle LTRIM() function is used to remove all specified characters from the left end side of a string. Optionally you can specify an initial character or characters to trim to, or it will default to a blank.

The CHR() function is used to insert control characters into a string. CHR(10) is used to insert line breaks, CHR(9) is for tabs, and CHR(13) is for carriage returns.

SQL Server is, by default case insensitive; however, it is possible to create a case sensitive SQL Server database and even to make specific table columns case sensitive. The way to determine a database or database object is by checking its “COLLATION” property and look for “CI” or “CS” in the result.

Which SQL is case sensitive? ›

The SQL keywords (SELECT, FROM, WHERE, etc.) are case-insensitive, yet they are frequently expressed in all capitals. Table and column names are case-sensitive in some settings. MySQL provides a setting that allows you to enable or disable it.

Table names are stored in lowercase on disk and name comparisons are not case-sensitive. MySQL converts all table names to lowercase on storage and lookup. This behavior also applies to database names and table aliases.