Listado de la etiqueta: Replace


Sometimes we wish to replace the substring of a string data field when managing a large database. We have the opportunity to remove the item and then re-adding it with a property. However, using replace in SQLite is a more efficient approach to accomplish this. The REPLACE statement in SQLite is used to discard and re-insert existing entries. The REPLACE SQLite command is a name for the command INSERT OR REPLACE INSERT.

The REPLACE statement in SQLite works on the idea that merienda UNIQUE or PRIMARY Key constraints fail, it will eliminate the problematic entry and insert a new row. In SQLite, the REPLACE command usually performs a two-step operation. The first one is it starts by deleting the record that violates the constraint and the second one is to add another row. So, if there is a constraint violation in the second step when inserting a new entry, the transaction will be rolled back.

With an example, we’ll learn about SQLite Replace statements and how to use them to remove and reinsert existing entries.

Syntax of the REPLACE statement in SQLite:

The SQLite Replace operation has the following syntax.

>> REPLACE( string, find the SUBSTRING, REPLACE WITH NEW string)

It works by passing three arguments: the “string” containing the substring to be replaced. The “substring” inside that text to be replaced, as well as the string to be “replaced” with the new string.

How to use REPLACE statement in SQLite:

Here, we go with some SQLite replace operation examples and see the usage of it in SQLite. Note that Case-sensitive replacement is taken into account when using the replace function.

We have a simple REPLACE operation in the following figure. First, we need a SELECT statement and then use a REPLACE function to which we have passed three arguments. The first argument is the string “Apple juice” and the second argument is the “Apple” which we want to replace. This “Apple” is a substring from the given string and the third argument is passed with a new string “orange” which is replaced by the substring “Apple”. The following query results are shown in the picture as follows:

>> SELECT REPLACE(‘Apple juice’, ‘Apple’, ‘Orange’);

We have our second REPLACE case which also takes three arguments. The first is the string “chicken burger”, next we have substring as “Pizza” which is not the part of the string we have defined. Notice that nothing is changed and the llamativo text is returned if the second parameter is not found in the first argument. The figure shows the query of the REPLACE function and its corresponding results.

>> SELECT REPLACE(‘Chicken Burger’, ‘Pizza’, ‘Pattie’);

This one is our third case in which we have our second argument is an empty string. Here, also the REPLACE function changes nothing but returns the source string which we have specified.

>> SELECT REPLACE(‘Diamond Ring’, », ‘Gold’);

However, this cannot be true of the third argument. If that string is empty and the first argument contains the second argument. The second argument will be removed from the string as follows:

>> SELECT REPLACE(‘yellow Light’, ‘yellow’, »);

If the string does not contain our second argument, it returns the string.

>> SELECT REPLACE(‘Vitamin C’, ‘Iron’, »);

Now, here we are replacing a string with the integer value which is possible in the REPLACE function of SQLite. The result is showing that the string is replaced with the number values.

>> SELECT REPLACE(‘ID number’, ‘number’, 8);

Example 1: Create a table for using REPLACE function:

We have created a table that is represented as “creams”. We have assigned three columns to this table and also set their data types. Showing the image below, the table is created successfully.

CREATE TABLE creams(
      cream_id INT PRIMARY KEY    ,
      cream_name           CHAR(10)   ,
      cream_price          FLOAT          
   
    );

Then, we have inserted the values against each column in the table “creams” as follows:

INSERT INTO creams VALUES (1, ‘ice-cream’, 300 );
INSERT INTO creams VALUES (2, ‘chocolate-cream’, 600);
INSERT INTO creams VALUES (3, ‘cheese-cream’, 560);
INSERT INTO creams VALUES (4, ‘caramel-cream’, 600);
INSERT INTO creams VALUES (5, ‘nuts-cream’, 450 );

To view the table record, just use the following query and the table record will be displayed as below.

Example 2: Using REPLACE function within the UPDATE statement:

There, we have an UPDATE statement which we have applied to the table “creams”. The update statement sets the values of the table column “cream_name” by calling the SET operator. To the SET operator, we have assigned a REPLACE function and inside the REPLACE function, we have passed three arguments. The first argument is the column name “cream_name” in which we want a replacement. Then, the string “cream” is used as a second argument on which replacement will be implemented. When the REPLACE function finds the string “cream” from the column “cream_name” of the table “creams”, it should change it with the new string “mayo”. The REPLACE function takes the string “mayo” as the third input.

UPDATE
    creams
SET
    cream_name = REPLACE(cream_name,‘cream’,‘mayo’);

The changes occur successfully in the following result screen.

Example 3: Using REPLACE function on the unique index in SQLite:

The “cream name” column of the table “creams” will be used to generate an index. I have used the SQLite query below to create a unique index on the field “cream name.”

>> CREATE UNIQUE INDEX idx_creams_cream_name  ON creams(cream_name);

Now, we will add a constraint for adding the name of the cream to the table “cream”. If the cream name already exists, it should update that entry. Otherwise, it will need to enter a new cream name. We have simply added this feature by utilizing the SQLite Replace statement as follows.

REPLACE INTO creams (cream_id ,cream_name,cream_price )
VALUES (6,‘Garlic-cream’, 200);

As the cream_name “Garlic-mayo” does not exist in the table “creams”, the following SQLite REPLACE statement introduces a new row into it. Upon running the select statement, the SQLite shell executes the record of the table creams with the newly inserted record.

Conclusion:

That is the performance of the SQLite Replace function to retrieve the data which we require according to our specifications. We have defined the REPLACE function syntax that we use in SQLite. Then, we have explored some different cases to show how the REPLACE function responds to these cases. At last, we have instances of REPLACE function that we use in the SQLite table.



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“In this article, we will be discussing the string replace method in the System namespace of the C# programming language. The Replace() method works on the string variable by replacing them with the definition of the parameter. It is a very beneficial method as it would reduce the process of deleting and creating new strings altogether and saves us a hassle by simply allowing us to edit the content of the strings.”

Example 01: Replacing Blank Spaces Into Characters in a String Using the Replace() Function in Ubuntu 20.04

In this example, we will be discussing the use of replace function in a string through which we will be replacing blank spaces of a string variable into a character. The replace function will transform the old string and convert it into a new transformed string. After its transformation, we will analyze the difference between the old and the new string.

In the C# program, we initialized the string variable and assigned some text with blank spaces in between. Then we printed out the old string variable and transformed the old string variable using the replace function. In the replace function, we gave the blank spaces as the first parameter, and in the second parameter, we gave the character “,” to be replaced in the old string. This program will transform the old string variable by putting commas in place of the blank spaces. The replace function will be called inline of the printing of the new variable; it will transform the old spring and save the new value in it.

Text Description automatically generated

After compiling and executing the above C# program, we will get the following output as shown in the above snippet. As we can see in the output, the old thing had blank spaces between the letters, and after it was transformed, the blank spaces were replaced by commas “,”, this turned out to be a more refined look for the string variable.

Example 02: Correcting the Spelling of a Word in a String Variable Using the Replace Function in Ubuntu 20.04

This example will be focused on the grammatical or writing error overstrain variable in our programs and how we can edit them by simple function in the C sharp programming language. In this example, we will see how a part of a string that is being repeated multiple times can be corrected by the replace function. We will implement this example in the Ubuntu 20.04 environment to get a better understanding.

Text Description automatically generated

This is the program that we will follow for replacing a word that is spelled wrong in a string variable with the correctly spelled word. First, we will initialize a string variable and assign some text to it, but this text will have some spelling mistakes in it. Then we will print it out on the display screen for visual differences with the new string that we are creating. A new string variable will be initialized in which we will use the replace function on the old string, and in the parameter brackets, we will write the wrong spelled word in the first expression and the correctly spelled word in the second expression.

After compiling and executing the following program on the command line in the terminal of Ubuntu 20.04, we will get the following output:

Text Description automatically generated

As the output reflects the flamante string had the word “file” spelled wrong, after using the replace function and successfully correcting the spelling of the word “file” by placing it down in the parameters, we get the correct output for this string variable that we intended.

Example 03: Replacing Text of a String to Characters by Using the Replace Function in Ubuntu 20.04

In this example, we will be discussing the method for replacing the textual part of a string with some characters. The replace function allows different sets of parameters, so we can replace every aspect of the string with whatever property we like. In this example, a string variable will be Initialized, and some text will be assigned to it. After this, we will replace the text with some characters by using the replace function so let’s implement this in the C# programming language.

Text Description automatically generated

In the above piece of code, we have initialized a string variable labeled “s.” This string variable will then be printed and its flamante form; after this, we will be using the replace function to transform the last part of the string variable’s text into some characters, and this transformation will also be printed out. Then we will use the replace function merienda again, and this time the initial part of the text in this string variable will be transformed into some characters; this replacement will also be printed out to provide a visual difference between the old and new string.

Text Description automatically generated

If we compile and execute the above program, we will get the exact output as shown in the above snippet. As we can see, the string variable was partially replaced by some characters and then called again to be replaced with some characters.

Example 04: Chain Calling the Replace Function to Replace Letters Multiple Times in a String in Ubuntu 20.04

The Replace function can call itself repeatedly multiple times in one single line. We can use this property to utilize the replace function as an encryption mechanism as well. The chain call property will be used to make repetitive replacements to a string variable. We will implement this example in the Ubuntu 20.04 environment.

Text Description automatically generated

In this C# program, we will be implementing the chain calling of the Replace() Function to make multiple changes to a string variable. We will initialize a string variable with some characters in it and print it. Then we will call the replace function multiple times to replace the string variable’s alphabets with other alphabets.

The result of the compilation and execution of the C# program will give the following output:

Text Description automatically generated

As the output suggests that the alphabet “A” has been replaced with the alphabet “D.” We called the Replace function three times, and every time we replaced the alphabets in a descending order that is “A” to “B” to “C” to “D.”

Example 05: Replacing a Word and a Character in a String Variable Using the Replace Function in Ubuntu 20.04

The use of Replace function to alter a sentence will be examined in this example. We will first replace a wrongly spelled word with a correctly spelled word, and after this, we will replace a character with a blank space and make the string variable orderly and correct.

Text, letter Description automatically generated

In this program, we initialized a string variable with some text assigned to it, then we corrected the spelling of the word “file” in the text, and then we used the replace function again to replace the “,” with a blank space to filter the string variable and make it proper.

Text Description automatically generated

After compiling and executing the program, we will get the above output. In this output, we can see the transition of the string variable from one replace function to the other, filtering out all the errors in the text.

Conclusion

In this article, we discussed the Replace() function for the string variable used in C# programming. The Replace() function is utilized to replace a part of a string with the use of parameters. We implemented the string Replace() function in the C# programming language and studied the changes it can create to a string in the Ubuntu 20.04 environment.



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