Why am I getting the \'mysqli_stmt::bind_param(): Mismatch in Character Count and Bind Variables\' error in my prepared statement?

mysqli_stmt::bind_param(): Mismatch in Character Count and Bind Variables

When attempting to insert data into a database using mysqli prepared statements, you may encounter the error "Number of elements in type definition string doesn't match number of bind variables." This error occurs when there is a mismatch between the number of placeholder markers (?) in the SQL query and the number of characters in the type definition string passed to bind_param.

In the example provided, there are 65 placeholder markers in the query and 65 variables being passed to bind_param. However, the type definition string is not specified in the code snippet, so it's impossible to verify whether the number of characters matches the number of bind variables.

The type definition string must contain the same number of characters as placeholders in the SQL query, where each character represents the data type of the corresponding placeholder. For example, in an SQL query with three placeholders, bind_param would require a type definition string with three characters, such as "sss" to indicate that all three placeholders are strings.

To resolve the error, ensure that:

• The SQL query contains the correct number of placeholder markers.
• The type definition string provided to bind_param matches the number of placeholder markers and specifies the correct data type for each placeholder.

Here's a corrected example with the type definition string included:

// Preparing our query statement via mysqli which will auto-escape all bad characters to prevent injection
$query3 = 'INSERT INTO datashep_AMS.COMPLETE_APPLICATIONS (
    project_name,
    status,
    funding_requested,
    project_title,
    program,
    county,
    parish,
    name_of_watercourse,
    which_is_a_tributary_of,
    name_of_applicant,
    contact_person_or_project_supervisor,
    relationship_to_organization,
    business_phone,
    home_phone,
    email,
    signature_of_thesis_or_study_supervisor,
    mailing_address,
    postal_code,
    website,
    mailing_address_for_payment,
    hst_registration_no,
    total_cost_dollar,
    total_cost_percent,
    dollar_amount_requested_from_nbwtf,
    percent_amount_requested_from_nbwtf,
    descriptive_summary,
    background_of_organization,
    mandate,
    years_in_existence,
    membership,
    accomplishments,
    previous_project_name,
    previous_project_number,
    previous_project_amount_received_from_nbwtf,
    summary_of_activities,
    summary_of_Results,
    project_title_2,
    reason_and_or_purpose,
    objectives,
    project_description,
    methods,
    equipment_and_materials_required,
    personnel_required,
    proposed_start_date,
    proposed_end_date,
    type_of_data_to_be_stored,
    where_will_it_be_housed,
    monitoring,
    short_term_achievement,
    long_term_achievement,
    previous_studies,
    required_permits,
    consultants,
    short_term_commitment,
    long_term_commitment,
    project_duration,
    project_evaluation,
    promotion_of_project,
    promotion_of_client,
    publication_of_results,
    community_benefits,
    effects_on_traditional_uses,
    possible_changes_in_public_access_to_areas,
    possible_impact_on_wildlife_and_or_environment,
    likelihood_of_future_requests_for_funding,
    list_all_other_funding_sources_for_this_project
) VALUES (
    ?,
    ?,
    ?,
    ?,
    ?,
    ?,
    ?,
    ?,
    ?,
    ?,
    ?,
    ?,
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    ?,
    ?,
    ?,
    ?
)';

// "Preparing" the query using mysqli->prepare(query) -- which is the equivalent of mysql_real_escape_string -- in other words, it's the SAFE database injection method
$stmt = $dbConnection->prepare($query3);

// "Bind_param" == replace all the "?"'s in the aforementioned query with the variables below

$stmt->bind_param(
    "ssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss", 
    $project_name, $status, $funding_requested, $project_title, $program, $county, $parish, $name_of_watercourse, $which_is_a_tributary_of, 
    $name_of_applicant, $contact_person_or_project_supervisor, $relationship_to_organization, $business_phone, $home_phone, $email, 
    $signature_of_thesis_or_study_supervisor, $mailing_address, $postal_code, $website, $mailing_address_for_payment, $hst_registration_no, 
    $total_cost_dollar, $total_cost_percent, $dollar_amount_requested_from_nbwtf, $percent_amount_requested_from_nbwtf, $descriptive_summary, 
    $background_of_organization, $mandate, $years_in_existence, $membership, $accomplishments, $previous_project_name, $previous_project_number, 
    $previous_project_amount_received_from_nbwtf, $summary_of_activities, $summary_of_Results, $project_title_2, $reason_and_or_purpose, $objectives, 
    $project_description, $methods, $equipment_and_materials_required, $personnel_required, $proposed_start_date, $proposed_end_date, 
    $type_of_data_to_be_stored, $where_will_it_be_housed, $monitoring, $short_term_commitment, $long_term_achievement, $previous_studies, $required_permits, 
    $consultants, $short_term_commitment, $long_term_commitment, $project_duration, $project_evaluation, $promotion_of_project, $promotion_of_client, 
    $publication_of_results, $community_benefits, $effects_on_traditional_uses, $possible_changes_in_public_access_to_areas, $possible_impact_on_wildlife_and_or_environment, 
    $likelihood_of_future_requests_for_funding, $list_all_other_funding_sources_for_this_project
);

// Perform the actual query!
$stmt->execute();

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