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MySql - DDL
In the context of database management and SQL (Structured Query Language), MySQL DDL (Data Definition Language) statements fall under the broader category of "Database Management" or "Database Operations." Specifically, DDL refers to the subset of SQL statements used to define the structure of databases and database objects such as tables, indexes, views, and schemas.
DDL statements in MySQL include commands like CREATE, ALTER, DROP, TRUNCATE, and RENAME, among others. These statements are essential for creating and modifying the structure of databases and their components, ensuring data integrity, and managing data definitions efficiently.
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06:11min
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Create Table
In the context of database management and SQL (Structured Query Language), MySQL DDL (Data Definition Language) statements fall under the broader category of "Database Management" or "Database Operations." Specifically, DDL refers to the subset of SQL statements used to define the structure of databases and database objects such as tables, indexes, views, and schemas.
DDL statements in MySQL include commands like `CREATE`, `ALTER`, `DROP`, `TRUNCATE`, and `RENAME`, among others. These statements are essential for creating and modifying the structure of databases and their components, ensuring data integrity, and managing data definitions efficiently.
Understanding MySQL DDL is crucial for database administrators and developers tasked with designing and maintaining databases, as it forms the foundation for organizing and manipulating data within MySQL databases effectively.
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03:40min
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Insert Data
In SQL databases such as MySQL, inserting data into a table is a fundamental operation categorized under Data Manipulation Language (DML). Using the `INSERT INTO` statement, developers add new rows of data into specified columns of a table. This statement requires specifying the table name and the values to be inserted, ensuring accurate placement of data according to defined column constraints and data types. Mastering `INSERT INTO` enables efficient management of database records, supporting robust data handling and manipulation within SQL environments.
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05:27min
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Alter Table
In SQL databases such as MySQL, the `ALTER TABLE` statement is a critical component of Data Definition Language (DDL), used to modify the structure of existing database tables. This statement allows database administrators and developers to add new columns (`ADD`), modify existing columns (`ALTER COLUMN`), drop columns (`DROP COLUMN`), add constraints like primary keys or foreign keys (`ADD CONSTRAINT`), and perform other structural changes to tables. `ALTER TABLE` is essential for evolving database schemas to accommodate changing business requirements or optimizing database performance. Mastering the use of `ALTER TABLE` ensures effective database management, supporting scalability and adaptability in SQL environments.
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04:51min
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DML Update
In SQL databases such as MySQL, the `ALTER TABLE` statement is a critical component of Data Definition Language (DDL), used to modify the structure of existing database tables. This statement allows database administrators and developers to add new columns (`ADD`), modify existing columns (`ALTER COLUMN`), drop columns (`DROP COLUMN`), add constraints like primary keys or foreign keys (`ADD CONSTRAINT`), and perform other structural changes to tables. `ALTER TABLE` is essential for evolving database schemas to accommodate changing business requirements or optimizing database performance. Mastering the use of `ALTER TABLE` ensures effective database management, supporting scalability and adaptability in SQL environments.
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02:43min
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Delete
In SQL databases such as MySQL, the `DELETE` statement is a core element of Data Manipulation Language (DML) used to remove data from tables. This statement allows developers and database administrators to delete specific rows from a table based on specified conditions using SQL syntax. The `DELETE` statement is structured as `DELETE FROM table_name WHERE condition`, where `table_name` identifies the table from which rows are to be removed, and `WHERE condition` specifies the criteria for selecting which rows to delete. Mastery of the `DELETE` statement is essential for maintaining data integrity, managing database storage efficiently, and adhering to data retention policies within database-driven applications. It provides robust capabilities for data manipulation and ensures the accuracy and consistency of data across systems.
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0:50min
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NotNullUnique
In the context of SQL databases, the terms NOT NULL and UNIQUE are constraints that are typically specified when defining columns within a table. These constraints fall under the broader category of "Data Definition Language" (DDL).
NOT NULL: This constraint specifies that a column must contain a value and cannot be null (i.e., empty or undefined). When defining a column, NOT NULL ensures that every row in the table must have a value for that column.
UNIQUE: This constraint ensures that all values in a column (or a combination of columns) are unique across the table. It prevents duplicate values from being entered into the specified column(s).
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04:40min
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PrimaryKey_ForeignKey
In SQL databases like MySQL, PRIMARY KEY and FOREIGN KEY constraints fall under the category of Data Definition Language (DDL). These constraints are used to define relationships and enforce data integrity within database tables.
PRIMARY KEY: This constraint uniquely identifies each row in a table. A primary key must contain unique values and cannot contain NULL values. It is defined on one or more columns in a table and ensures that each row is uniquely identifiable.
FOREIGN KEY: This constraint is used to link two tables together. A foreign key in one table points to a primary key in another table, establishing a relationship between the two tables. This helps maintain referential integrity by ensuring that values in the foreign key column correspond to valid values in the referenced primary key column.
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04:48min
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