September 2017 Update
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Ingy döt Net
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commit
ba8067c3b7
14570 changed files with 153136 additions and 63871 deletions
114
Task/Parametrized-SQL-statement/C/parametrized-sql-statement.c
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114
Task/Parametrized-SQL-statement/C/parametrized-sql-statement.c
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#include <stdio.h>
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#include <stdlib.h>
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#include <sqlite3.h>
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static const char* db_file = ":memory:"; // Create an in-memory database.
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void check_error(int result_code, sqlite3 *db);
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int select_callback(void* data, int column_count, char** columns, char** column_names);
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int main(void) {
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sqlite3 *db;
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int result_code;
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char *sql;
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char *insert_statements[4];
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sqlite3_stmt *compiled_statement;
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int i;
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// Open the database.
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result_code = sqlite3_open(db_file, &db);
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check_error(result_code, db);
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// Create the players table in the database.
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sql = "create table players("
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"id integer primary key asc, "
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"name text, "
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"score real, "
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"active integer, " // Store the bool value as integer (see https://sqlite.org/datatype3.html chapter 2.1).
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"jerseyNum integer);";
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result_code = sqlite3_exec(db, sql, NULL, NULL, NULL);
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check_error(result_code, db);
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// Insert some values into the players table.
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insert_statements[0] = "insert into players (name, score, active, jerseyNum) "
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"values ('Roethlisberger, Ben', 94.1, 1, 7);";
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insert_statements[1] = "insert into players (name, score, active, jerseyNum) "
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"values ('Smith, Alex', 85.3, 1, 11);";
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insert_statements[2] = "insert into players (name, score, active, jerseyNum) "
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"values ('Manning, Payton', 96.5, 0, 18);";
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insert_statements[3] = "insert into players (name, score, active, jerseyNum) "
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"values ('Doe, John', 15, 0, 99);";
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for (i=0; i<4; i++) {
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result_code = sqlite3_exec(db, insert_statements[i], NULL, NULL, NULL);
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check_error(result_code, db);
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}
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// Display the contents of the players table.
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printf("Before update:\n");
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sql = "select * from players;";
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result_code = sqlite3_exec(db, sql, select_callback, NULL, NULL);
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check_error(result_code, db);
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// Prepare the parametrized SQL statement to update player #99.
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sql = "update players set name=?, score=?, active=? where jerseyNum=?;";
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result_code = sqlite3_prepare_v2(db, sql, -1, &compiled_statement, NULL);
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check_error(result_code, db);
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// Bind the values to the parameters (see https://sqlite.org/c3ref/bind_blob.html).
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result_code = sqlite3_bind_text(compiled_statement, 1, "Smith, Steve", -1, NULL);
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check_error(result_code, db);
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result_code = sqlite3_bind_double(compiled_statement, 2, 42);
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check_error(result_code, db);
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result_code = sqlite3_bind_int(compiled_statement, 3, 1);
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check_error(result_code, db);
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result_code = sqlite3_bind_int(compiled_statement, 4, 99);
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check_error(result_code, db);
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// Evaluate the prepared SQL statement.
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result_code = sqlite3_step(compiled_statement);
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if (result_code != SQLITE_DONE) {
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printf("Error #%d: %s\n", result_code, sqlite3_errmsg(db));
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sqlite3_close(db);
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return result_code;
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}
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// Destroy the prepared statement object.
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result_code = sqlite3_finalize(compiled_statement);
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check_error(result_code, db);
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// Display the contents of the players table.
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printf("After update:\n");
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sql = "select * from players;";
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result_code = sqlite3_exec(db, sql, select_callback, NULL, NULL);
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check_error(result_code, db);
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// Close the database connection.
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sqlite3_close(db);
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return EXIT_SUCCESS;
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}
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/*
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Checks the result code from an SQLite operation.
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If it contains an error code then this function prints the error message,
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closes the database and exits.
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*/
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void check_error(int result_code, sqlite3 *db) {
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if (result_code != SQLITE_OK) {
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printf("Error #%d: %s\n", result_code, sqlite3_errmsg(db));
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sqlite3_close(db);
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exit(result_code);
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}
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}
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/* This callback function prints the results of the select statement. */
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int select_callback(void* data, int column_count, char** columns, char** column_names) {
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int i;
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for (i=0; i<column_count; i++) {
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printf(columns[i]);
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if (i < column_count-1) printf(" | ");
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}
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printf("\n");
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}
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@ -0,0 +1,124 @@
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program Parametrized_SQL_Statement;
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uses
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sqlite3, sysutils;
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const
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DB_FILE : PChar = ':memory:'; // Create an in-memory database.
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var
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DB :Psqlite3;
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ResultCode :Integer;
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SQL :PChar;
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InsertStatements :array [1..4] of PChar;
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CompiledStatement :Psqlite3_stmt;
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i :integer;
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{ CheckError
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Checks the result code from an SQLite operation.
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If it contains an error code then this procedure prints the error message,
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closes the database and halts the program. }
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procedure CheckError(ResultCode: integer; DB: Psqlite3);
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begin
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if ResultCode <> SQLITE_OK then
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begin
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writeln(format('Error #%d: %s', [ResultCode, sqlite3_errmsg(db)]));
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sqlite3_close(DB);
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halt(ResultCode);
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end;
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end;
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{ SelectCallback
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This callback function prints the results of the select statement.}
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function SelectCallback(Data: pointer; ColumnCount: longint; Columns: PPChar; ColumnNames: PPChar):longint; cdecl;
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var
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i :longint;
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col :PPChar;
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begin
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col := Columns;
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for i:=0 to ColumnCount-1 do
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begin
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write(col^); // Print the current column value.
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inc(col); // Advance the pointer.
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if i<>ColumnCount-1 then write(' | ');
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end;
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writeln;
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end;
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begin
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// Open the database.
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ResultCode := sqlite3_open(DB_FILE, @DB);
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CheckError(ResultCode, DB);
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// Create the players table in the database.
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SQL := 'create table players(' +
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'id integer primary key asc, ' +
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'name text, ' +
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'score real, ' +
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'active integer, ' + // Store the bool value as integer (see https://sqlite.org/datatype3.html chapter 2.1).
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'jerseyNum integer);';
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ResultCode := sqlite3_exec(DB, SQL, nil, nil, nil);
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CheckError(ResultCode, DB);
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// Insert some values into the players table.
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InsertStatements[1] := 'insert into players (name, score, active, jerseyNum) ' +
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'values (''Roethlisberger, Ben'', 94.1, 1, 7);';
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InsertStatements[2] := 'insert into players (name, score, active, jerseyNum) ' +
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'values (''Smith, Alex'', 85.3, 1, 11);';
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InsertStatements[3] := 'insert into players (name, score, active, jerseyNum) ' +
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'values (''Manning, Payton'', 96.5, 0, 18);';
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InsertStatements[4] := 'insert into players (name, score, active, jerseyNum) ' +
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'values (''Doe, John'', 15, 0, 99);';
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for i:=1 to 4 do
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begin
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ResultCode := sqlite3_exec(DB, InsertStatements[i], nil, nil, nil);
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CheckError(ResultCode, DB);
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end;
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// Display the contents of the players table.
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writeln('Before update:');
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SQL := 'select * from players;';
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ResultCode := sqlite3_exec(DB, SQL, @SelectCallback, nil, nil);
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CheckError(ResultCode, DB);
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// Prepare the parametrized SQL statement to update player #99.
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SQL := 'update players set name=?, score=?, active=? where jerseyNum=?;';
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ResultCode := sqlite3_prepare_v2(DB, SQL, -1, @CompiledStatement, nil);
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CheckError(ResultCode, DB);
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// Bind the values to the parameters (see https://sqlite.org/c3ref/bind_blob.html).
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ResultCode := sqlite3_bind_text(CompiledStatement, 1, PChar('Smith, Steve'), -1, nil);
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CheckError(ResultCode, DB);
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ResultCode := sqlite3_bind_double(CompiledStatement, 2, 42);
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CheckError(ResultCode, DB);
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ResultCode := sqlite3_bind_int(CompiledStatement, 3, 1);
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CheckError(ResultCode, DB);
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ResultCode := sqlite3_bind_int(CompiledStatement, 4, 99);
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CheckError(ResultCode, DB);
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// Evaluate the prepared SQL statement.
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ResultCode := sqlite3_step(CompiledStatement);
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if ResultCode <> SQLITE_DONE then
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begin
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writeln(format('Error #%d: %s', [ResultCode, sqlite3_errmsg(db)]));
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sqlite3_close(DB);
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halt(ResultCode);
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end;
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// Destroy the prepared statement object.
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ResultCode := sqlite3_finalize(CompiledStatement);
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CheckError(ResultCode, DB);
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// Display the contents of the players table.
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writeln('After update:');
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SQL := 'select * from players;';
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ResultCode := sqlite3_exec(DB, SQL, @SelectCallback, nil, nil);
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CheckError(ResultCode, DB);
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// Close the database connection.
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sqlite3_close(db);
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end.
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@ -0,0 +1,40 @@
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-- This works in Oracle's SQL*Plus command line utility
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VARIABLE P_NAME VARCHAR2(20);
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VARIABLE P_SCORE NUMBER;
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VARIABLE P_ACTIVE VARCHAR2(5);
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VARIABLE P_JERSEYNUM NUMBER;
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begin
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:P_NAME := 'Smith, Steve';
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:P_SCORE := 42;
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:P_ACTIVE := 'TRUE';
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:P_JERSEYNUM := 99;
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end;
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/
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drop table players;
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create table players
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(
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NAME VARCHAR2(20),
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SCORE NUMBER,
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ACTIVE VARCHAR2(5),
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JERSEYNUM NUMBER
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);
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insert into players values ('No name',0,'FALSE',99);
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commit;
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select * from players;
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UPDATE players
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SET name = :P_NAME, score = :P_SCORE, active = :P_ACTIVE
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WHERE jerseyNum = :P_JERSEYNUM;
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commit;
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select * from players;
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