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5 min readOne way to prevent the input of certain letters using Oracle is by creating a check constraint on the table column where the input is being made. You can use regular expressions to define the pattern of allowed characters and disallow certain letters. For example, you can use the REGEXP_LIKE function to check if the input contains any of the disallowed letters and raise an error if it does. Additionally, you can use triggers to validate the input before it is inserted or updated in the database.
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4 min readTo run a stored procedure in Oracle, you first need to ensure that the stored procedure has been created and is stored within the Oracle database. Once the stored procedure is created, you can run it by using the following steps:Connect to the Oracle database using a tool such as SQL*Plus, SQL Developer, or any other compatible tool.Once connected, you can execute the stored procedure by typing the command to call the procedure followed by any necessary parameters.
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8 min readTo create an inheritance table in Oracle, you can use the concept of table partitioning to achieve inheritance-like behavior. Essentially, you create a parent table that contains all the common columns and then create child tables that inherit from the parent table. Each child table contains specific columns unique to that child entity.To create a parent table, you can use the CREATE TABLE statement with the necessary columns.
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3 min readTo call a function in Oracle, you can simply use the function name followed by parentheses that may or may not contain input parameters.
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3 min readTo use the ABS function with percentages in Oracle, you simply apply the ABS function to the percentage value. The ABS function returns the absolute value of a number, regardless of its sign. This means that if you have a negative percentage value, applying the ABS function will make it positive.
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7 min readTo convert two or more rows into columns in Oracle, you can use the PIVOT clause. This allows you to aggregate values from multiple rows of a table into a single row. You first need to identify the unique identifier for each row that needs to be converted into columns. Then you can use the PIVOT clause along with an aggregation function to pivot the rows into columns based on this identifier.
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5 min readIn Oracle, you can group varchar type columns in a query by using the GROUP BY clause. The GROUP BY clause is used in conjunction with aggregate functions such as COUNT, SUM, AVG, etc. to group the results based on the values in one or more varchar type columns. When grouping varchar type columns, Oracle will treat each unique value in the column as a separate group, and the aggregate functions will be applied to each group separately.
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3 min readTo change the data type of a column in Oracle, you can use the ALTER TABLE statement with the MODIFY clause. First, identify the table and column you want to modify. Then, use the following syntax: ALTER TABLE table_name MODIFY column_name new_data_type; Replace table_name with the name of the table, column_name with the name of the column you want to modify, and new_data_type with the new data type you want to change the column to.
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5 min readTo split a table rows into fixed size chunks in Oracle, you can use the ROW_NUMBER() function and integer division to assign each row to a chunk. You can then query the table using a common table expression to select rows based on the assigned chunk number. By adjusting the chunk size and filtering criteria, you can control the size and content of each chunk. This method allows you to split a large table into smaller, more manageable chunks for processing or analysis.
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6 min readTo group multiple records into a single record in Oracle, you can use the GROUP BY clause along with aggregate functions such as SUM, COUNT, AVG, etc. This allows you to consolidate data from multiple rows into a single row based on a specific column or columns. By defining the grouping criteria in the GROUP BY clause, Oracle will combine the rows with matching values into a single record. You can also use the HAVING clause to further filter the grouped data based on specified conditions.
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8 min readTo connect a PostgreSQL database to Oracle, you can use a tool like ODBC (Open Database Connectivity) or JDBC (Java Database Connectivity). With ODBC, you can set up a System DSN (Data Source Name) in Windows to connect to both databases. You will need to install the appropriate ODBC driver for PostgreSQL and Oracle, and then configure the connection settings in the ODBC Data Source Administrator.Alternatively, you can use JDBC to connect to both databases programmatically in Java.