Package com.mckoi.database.interpret
Class AlterTable
java.lang.Object
com.mckoi.database.interpret.Statement
com.mckoi.database.interpret.AlterTable
Logic for the ALTER TABLE SQL statement.
- Author:
- Tobias Downer
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Field Summary
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoid
addAction
(AlterTableAction action) Adds an action to perform in this alter statement.boolean
checkColumnNamesMatch
(DatabaseConnection db, String col1, String col2) Returns true if the column names match.evaluate()
Evaluates the statement and returns a table that represents the result set.void
prepare()
Prepares the statement with the given Database object.Methods inherited from class com.mckoi.database.interpret.Statement
addTable, Debug, init, resolveTree, resolveVariableName
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Constructor Details
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AlterTable
public AlterTable()
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Method Details
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addAction
Adds an action to perform in this alter statement. -
checkColumnNamesMatch
Returns true if the column names match. If the database is in case insensitive mode then the columns will match if the case insensitive search matches. -
prepare
Description copied from class:Statement
Prepares the statement with the given Database object. This is called before the statement is evaluated. The prepare statement queries the database and resolves information about the statement (for example, it resolves column names and aliases and determines the tables that are touched by this statement so we can lock the appropriate tables before we evaluate).NOTE: Care must be taken to ensure that all methods called here are safe in as far as modifications to the data occuring. The rules for safety should be as follows. If the database is in EXCLUSIVE mode, then we need to wait until it's switched back to SHARED mode before this method is called. All collection of information done here should not involve any table state info. except for column count, column names, column types, etc. Queries such as obtaining the row count, selectable scheme information, and certainly 'getCellContents' must never be called during prepare. When prepare finishes, the affected tables are locked and the query is safe to 'evaluate' at which time table state is safe to inspect.
- Specified by:
prepare
in classStatement
- Throws:
DatabaseException
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evaluate
Description copied from class:Statement
Evaluates the statement and returns a table that represents the result set. This is called after 'prepare'.- Specified by:
evaluate
in classStatement
- Throws:
DatabaseException
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